file.content.limit 1048576 The length limit for downloaded content using the file:// protocol, in bytes. If this value is non-negative (>=0), content longer than it will be truncated; otherwise, no truncation at all. Do not confuse this setting with the http.content.limit setting. file.crawl.parent true The crawler is not restricted to the directories that you specified in the URLs file but it is jumping into the parent directories as well. For your own crawlings you can change this behavior (set to false) the way that only directories beneath the directories that you specify get crawled. file.crawl.redirect_noncanonical true If true, protocol-file treats non-canonical file names as redirects and does not canonicalize file names internally. A file name containing symbolic links as path elements is then not resolved and "fetched" but recorded as redirect with the canonical name (all links on path are resolved) as redirect target. file.content.ignored true If true, no file content will be saved during fetch. And it is probably what we want to set most of time, since file:// URLs are meant to be local and we can always use them directly at parsing and indexing stages. Otherwise file contents will be saved. !! NOT IMPLEMENTED YET !! http.agent.name 'User-Agent' name: a single word uniquely identifying your crawler. The value is used to select the group of robots.txt rules addressing your crawler. It is also sent as part of the HTTP 'User-Agent' request header. This property MUST NOT be empty - please set this to a single word uniquely related to your organization. Following RFC 9309 the 'User-Agent' name (aka. 'product token') "MUST contain only uppercase and lowercase letters ('a-z' and 'A-Z'), underscores ('_'), and hyphens ('-')." NOTE: You should also check other related properties: http.robots.agents http.agent.description http.agent.url http.agent.email http.agent.version and set their values appropriately. http.robots.agents Any other agents, apart from 'http.agent.name', that the robots parser would look for in robots.txt. Multiple agents can be provided using comma as a delimiter. eg. mybot,foo-spider,bar-crawler The ordering of agents does NOT matter and the robots.txt parser combines all rules to any of the agent names. Also, there is NO need to add a wildcard (ie. "*") to this string as the robots parser would smartly take care of a no-match situation. If no value is specified, by default HTTP agent (ie. 'http.agent.name') is used for user-agent matching by the robots parser. http.robot.rules.allowlist Comma separated list of hostnames or IP addresses to ignore robot rules parsing for. Use with care and only if you are explicitly allowed by the site owner to ignore the site's robots.txt! Also keep in mind: ignoring the robots.txt rules means that no robots.txt file is requested which may cause the following side effects: (1) undesired content (duplicates, private pages, etc.) excluded via robotst.txt rules is crawled, (2) the Crawl-Delay directive is ignored and (3) no sitemaps are detected. http.robots.403.allow true Some servers return HTTP status 403 (Forbidden) if /robots.txt doesn't exist. This should probably mean that we are allowed to crawl the site nonetheless. If this is set to false, then such sites will be treated as forbidden. http.robots.503.defer.visits true Temporarily suspend fetching from a host if the robots.txt response is HTTP 503 or any other 5xx server error and HTTP 429 Too Many Requests. See also http.robots.503.defer.visits.delay and http.robots.503.defer.visits.retries http.robots.503.defer.visits.delay 300000 Time in milliseconds to suspend crawling a host if the robots.txt response is HTTP 5xx or 429 Too Many Requests - see http.robots.503.defer.visits. http.robots.503.defer.visits.retries 3 Number of retries crawling a host if the robots.txt response is HTTP 5xx or 429 - see http.robots.503.defer.visits. After n retries the host queue is dropped for this segment/cycle. http.robots.redirect.max 5 Maximum number of redirects followed when fetching a robots.txt file. RFC 9309 specifies that "crawlers SHOULD follow at least five consecutive redirects, even across authorities (for example, hosts in the case of HTTP)." http.agent.description Further description of our bot- this text is used in the User-Agent header. It appears in parenthesis after the agent name. http.agent.url A URL to advertise in the User-Agent header. This will appear in parenthesis after the agent name. Custom dictates that this should be a URL to a page that explains the purpose and behavior of this crawler. http.agent.email An email address to advertise in the HTTP 'User-Agent' (and 'From') request headers. A good practice is to mangle this address (e.g. 'info at example dot com') to avoid spamming. http.agent.version Nutch-1.23 A version string to advertise in the User-Agent header. http.agent.rotate false If true, instead of http.agent.name, alternating agent names are chosen from a list provided via http.agent.rotate.file. http.agent.rotate.file agents.txt File containing alternative user-agent names to be used instead of http.agent.name on a rotating basis if http.agent.rotate is true. Each line of the file should contain exactly one agent specification including name, version, description, URL, etc. http.agent.host.cookie.file cookies.txt File containing per-host configured cookies. http.agent.host Name or IP address of the host on which the Nutch crawler would be running. Currently this is used by 'protocol-httpclient' plugin. http.timeout 10000 The default network timeout, in milliseconds. http.content.limit 1048576 The length limit for downloaded content using the http/https protocols, in bytes. If this value is non-negative (>=0), content longer than it will be truncated; otherwise, no truncation at all. Do not confuse this setting with the file.content.limit setting. http.time.limit -1 The time limit in seconds to fetch a single document. If this value is non-negative (>=0), the HTTP protocol implementation will stop reading from a socket after http.time.limit seconds have been spent for fetching this document. The HTTP response is then marked as truncated. The http.time.limit should be set to a longer time period than http.timeout, as it applies to the entire duration to fetch a document, not only the network timeout of a single I/O operation. Note: supported only by protocol-okhttp. http.partial.truncated false If true the HTTP protocol implementation may store the content of partial fetches and mark the response as truncated instead of throwing an exception which will cause the fetch to fail. This allows to use the data which has already been fetched, instead of retrying the fetch later. Note: supported only by protocol-okhttp. http.tls.certificates.check false Whether to check the TLS/SSL server certificates for validity. If true invalid (e.g., self-signed or expired) certificates are rejected and the https connection is failed. If false insecure TLS/SSL connections are allowed. Note that this property is currently not supported by all http/https protocol plugins. http.proxy.host The proxy hostname. If empty, no proxy is used. http.proxy.port The proxy port. http.proxy.username Username for proxy. This will be used by 'protocol-httpclient', if the proxy server requests basic, digest and/or NTLM authentication. To use this, 'protocol-httpclient' must be present in the value of 'plugin.includes' property. NOTE: For NTLM authentication, do not prefix the username with the domain, i.e. 'susam' is correct whereas 'DOMAIN\susam' is incorrect. http.proxy.password Password for proxy. This will be used by 'protocol-httpclient', if the proxy server requests basic, digest and/or NTLM authentication. To use this, 'protocol-httpclient' must be present in the value of 'plugin.includes' property. http.proxy.realm Authentication realm for proxy. Do not define a value if realm is not required or authentication should take place for any realm. NTLM does not use the notion of realms. Specify the domain name of NTLM authentication as the value for this property. To use this, 'protocol-httpclient' must be present in the value of 'plugin.includes' property. http.auth.file httpclient-auth.xml Authentication configuration file for 'protocol-httpclient' plugin. http.proxy.type HTTP Proxy type: HTTP or SOCKS (cf. java.net.Proxy.Type). Note: supported by protocol-okhttp. http.proxy.exception.list Either i) a comma separated list of hosts e.g., domain1.org,www.domain2.com, or ii) a wildcard '*' in either prefix e.g. "*.domain.com", or suffix e.g. "some.domain.*", that don't use the proxy (e.g. intranets) http.useHttp11 true If true, use HTTP 1.1, if false use HTTP 1.0 . http.useHttp2 false If true try HTTP/2 and fall-back to HTTP/1.1 if HTTP/2 not supported, if false use always HTTP/1.1. NOTE: HTTP/2 is currently only supported by protocol-okhttp and requires at runtime Java 9 and upwards or a modified Java 8 with support for ALPN (Application Layer Protocol Negotiation). http.accept.language en-us,en-gb,en;q=0.7,*;q=0.3 Value of the "Accept-Language" request header field. This allows selecting non-English language as default one to retrieve. It is a useful setting for search engines build for certain national group. To send requests without "Accept-Language" header field, this property must be configured to contain a space character because an empty property does not overwrite the default. http.accept text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Value of the "Accept" request header field. A space character as value will cause that no "Accept" header field is sent in the request. http.accept.charset utf-8,iso-8859-1;q=0.7,*;q=0.7 Value of the "Accept-Charset" request header field. A space character as value will cause that no "Accept-Charset" header field is sent in the request. http.store.responsetime true Enables us to record the response time of the host which is the time period between start connection to end connection of a pages host. The response time in milliseconds is stored in CrawlDb in CrawlDatum's meta data under key "_rs_" http.enable.if.modified.since.header true Whether Nutch sends an HTTP If-Modified-Since header. It reduces bandwidth when enabled by not downloading pages that respond with an HTTP Not-Modified header. URLs that are not downloaded are not passed through parse or indexing filters. If you regularly modify filters, you should force Nutch to also download unmodified pages by disabling this feature. http.enable.cookie.header true Whether Nutch sends an HTTP Cookie header. The cookie value is read from the CrawlDatum Cookie metadata field. http.connection.pool.okhttp (EXPERT) List of 3 integer values [M,N,T]: Instantiate protocol-okhttp with M connection pools of size N and a keep-alive time of T seconds. The product M*N should approx. correspond to the number of crawled hosts in one fetcher task during the keep-alive time. Because OkHttp's connection pool (v4.9.1) is not optimized for fast look-up of connections, the pool size N should not exceed 1000. To allow for efficient pooling, multiple pools are instantiated and connections are distributed over the pools by target host name. If the property is undefined or empty a single pool is used with OkHttp's default size and keep-alive time. For OkHttp 4.9.1 the default is equivalent to a configuration value "1,5,300" - one pool with 5 idle connections and 300 sec. keep-alive time. See also NUTCH-2896 and https://square.github.io/okhttp/3.x/okhttp/okhttp3/ConnectionPool.html http.filter.ipaddress.include If not empty: only fetch content from these IP addresses defined as a comma-separated list of a single IP address, a CIDR notation, or one of the following pre-defined IP address types: localhost, loopback, sitelocal. The property http.filter.ipaddress.exclude can be used to block subranges in the included list of ranges. Note: supported only by protocol-okhttp. http.filter.ipaddress.exclude If not empty: do not fetch content from these IP addresses defined as a comma-separated list of a single IP address, a CIDR notation, or one of the following pre-defined IP address types: localhost, loopback, sitelocal. Note: supported only by protocol-okhttp. ftp.username anonymous ftp login username. ftp.password anonymous@example.com ftp login password. ftp.content.limit 1048576 The length limit for downloaded content, in bytes. If this value is non-negative (>=0), content longer than it will be truncated; otherwise, no truncation at all. Caution: classical ftp RFCs never defines partial transfer and, in fact, some ftp servers out there do not handle client side forced close-down very well. Our implementation tries its best to handle such situations smoothly. ftp.timeout 60000 Default timeout for ftp client socket, in millisec. Please also see ftp.keep.connection below. ftp.server.timeout 100000 An estimation of ftp server idle time, in millisec. Typically it is 120000 millisec for many ftp servers out there. Better be conservative here. Together with ftp.timeout, it is used to decide if we need to delete (annihilate) current ftp.client instance and force to start another ftp.client instance anew. This is necessary because a fetcher thread may not be able to obtain next request from queue in time (due to idleness) before our ftp client times out or remote server disconnects. Used only when ftp.keep.connection is true (please see below). ftp.keep.connection false Whether to keep ftp connection. Useful if crawling same host again and again. When set to true, it avoids connection, login and dir list parser setup for subsequent URLs. If it is set to true, however, you must make sure (roughly): (1) ftp.timeout is less than ftp.server.timeout (2) ftp.timeout is larger than (fetcher.threads.fetch * fetcher.server.delay) Otherwise there will be too many "delete client because idled too long" messages in thread logs. ftp.follow.talk false Whether to log dialogue between our client and remote server. Useful for debugging. db.fetch.interval.default 2592000 The default number of seconds between re-fetches of a page (30 days). db.fetch.interval.max 7776000 The maximum number of seconds between re-fetches of a page (90 days). After this period every page in the db will be re-tried, no matter what is its status. db.fetch.schedule.class org.apache.nutch.crawl.DefaultFetchSchedule The implementation of fetch schedule. DefaultFetchSchedule simply adds the original fetchInterval to the last fetch time, regardless of page changes, whereas AdaptiveFetchSchedule (see below) tries to adapt to the rate at which a given page is changed. db.fetch.schedule.adaptive.inc_rate 0.4 If a page is unmodified, its fetchInterval will be increased by this rate. This value should not exceed 0.5, otherwise the algorithm becomes unstable. db.fetch.schedule.adaptive.dec_rate 0.2 If a page is modified, its fetchInterval will be decreased by this rate. This value should not exceed 0.5, otherwise the algorithm becomes unstable. db.fetch.schedule.adaptive.min_interval 60.0 Minimum fetchInterval, in seconds. db.fetch.schedule.adaptive.max_interval 31536000.0 Maximum fetchInterval, in seconds (365 days). NOTE: this is limited by db.fetch.interval.max. Pages with fetchInterval larger than db.fetch.interval.max will be fetched anyway. db.fetch.schedule.adaptive.sync_delta true If true, try to synchronize with the time of page change. by shifting the next fetchTime by a fraction (sync_rate) of the difference between the last modification time, and the last fetch time. db.fetch.schedule.adaptive.sync_delta_rate 0.3 See sync_delta for description. This value should not exceed 0.5, otherwise the algorithm becomes unstable. db.fetch.schedule.mime.file adaptive-mimetypes.txt The configuration file for the MimeAdaptiveFetchSchedule. db.update.additions.allowed true If true, updatedb will add newly discovered URLs, if false only already existing URLs in the CrawlDb will be updated and no new URLs will be added. db.preserve.backup true If true, updatedb will keep a backup of the previous CrawlDb version in the old directory. In case of disaster, one can rename old to current and restore the CrawlDb to its previous state. db.update.purge.404 false If true, updatedb will add purge records with status DB_GONE from the CrawlDb. db.update.purge.orphans false If true, updatedb will permanently delete URLs marked as orphan from the CrawlDb. The plugin scoring-orphan needs to be activated to get records marked as orphan. See the plugin's options elsewhere in this document. crawldb.url.normalizers false !Temporary, can be overwritten with the command line! Normalize URLs when updating CrawlDb crawldb.url.filters false !Temporary, can be overwritten with the command line! Filter URLs when updating CrawlDb db.update.max.inlinks 10000 Maximum number of inlinks to take into account when updating a URL score in the CrawlDb. Only the best scoring inlinks are kept. db.ignore.internal.links false If true, outlinks leading from a page to pages of the same host or domain will be ignored. See also 'db.ignore.external.links' and 'db.ignore.external.links.mode'. db.ignore.external.links false If true, outlinks leading from a page to an external host or domain will be ignored. This is an effective way to limit the crawl to include only initially injected hosts or domains, without creating complex URLFilters. See also 'db.ignore.external.links.mode'. db.ignore.also.redirects true If true, the fetcher checks redirects the same way as links when ignoring internal or external links. Set to false to follow redirects despite the values for db.ignore.external.links and db.ignore.internal.links. db.ignore.external.links.mode byHost Whether internal or external links are determined by host ('byHost') or domain ('byDomain'). See also the properties 'db.ignore.external.links' and 'db.ignore.internal.links'. db.ignore.external.exemptions.file db-ignore-external-exemptions.txt This file contains exemption rules used by 'urlfiter-ignoreexempt' plugin db.injector.overwrite false Whether existing records in the CrawlDb will be overwritten by injected records. db.injector.update false If true existing records in the CrawlDb will be updated with injected records. Old meta data is preserved. The db.injector.overwrite parameter has precedence. db.score.injected 1.0 The score of new pages added by the injector. db.score.link.external 1.0 The score factor for new pages added due to a link from another host relative to the referencing page's score. Scoring plugins may use this value to affect initial scores of external links. db.score.link.internal 1.0 The score factor for pages added due to a link from the same host, relative to the referencing page's score. Scoring plugins may use this value to affect initial scores of internal links. db.score.count.filtered false The score value passed to newly discovered pages is calculated as a fraction of the original page score divided by the number of outlinks. If this option is false, only the outlinks that passed URLFilters will count, if it's true then all outlinks will count. db.max.outlinks.per.page 100 The maximum number of outlinks that we'll process for a page. If this value is non-negative (>=0), at most db.max.outlinks.per.page outlinks will be processed for a page; otherwise, all outlinks will be processed. db.max.outlink.length 4096 The maximum length in characters accepted for outlinks before applying URL normalizers and filters. If this value is non-negative (>=0), only URLs with a length in characters less or equal than db.max.outlink.length are accepted and then passed to URL normalizers and filters. Doing the length check beforehand avoids that normalizers or filters hang up on overlong URLs. Note: this property is only used to check URLs found as outlinks and redirects, but not for injected URLs. db.parsemeta.to.crawldb Comma-separated list of parse metadata keys to transfer to the CrawlDb (NUTCH-779). Assuming for instance that the 'languageidentifier' plugin is enabled, setting the value to 'lang' will copy both the key 'lang' and its value to the corresponding entry in the CrawlDb. db.fetch.retry.max 3 The maximum number of times a URL that has encountered recoverable errors is generated for fetch. db.signature.class org.apache.nutch.crawl.MD5Signature The default implementation of a page signature. Signatures created with this implementation will be used for duplicate detection and removal. db.signature.text_profile.min_token_len 2 Minimum token length to be included in the signature. db.signature.text_profile.quant_rate 0.01 Profile frequencies will be rounded down to a multiple of QUANT = (int)(QUANT_RATE * maxFreq), where maxFreq is a maximum token frequency. If maxFreq > 1 then QUANT will be at least 2, which means that for longer texts tokens with frequency 1 will always be discarded. db.stats.score.quantiles .01,.05,.1,.2,.25,.3,.4,.5,.6,.7,.75,.8,.9,.95,.99 Quantiles of the distribution of CrawlDatum scores shown in the CrawlDb statistics (command `readdb -stats'). Comma-separated list of floating point numbers. linkdb.max.inlinks 10000 Maximum number of inlinks per URL to be kept in LinkDb. If "invertlinks" finds more inlinks than this number, only the first N inlinks will be stored, and the rest will be discarded. linkdb.ignore.internal.links true If true, when adding new links to a page, links from the same host are ignored. This is an effective way to limit the size of the link and anchor text database (LinkDb), keeping only the more descriptive external links and ignoring internal navigation links. linkdb.ignore.external.links false If true, when adding new links to a page in the LinkDb, links from a different host are ignored. linkdb.max.anchor.length 100 The maximum number of characters permitted for anchor texts stored in LinkDb. generate.max.count -1 The maximum number of URLs in a single fetchlist. -1 if unlimited. The URLs are counted according to the value of the parameter generate.count.mode. generate.count.mode host Determines how the URLs are counted for generate.max.count. Default value is 'host' but can be 'domain'. Note that we do not count per IP in the new version of the Generator. generate.update.crawldb false For highly-concurrent environments, where several generate/fetch/update cycles may overlap, setting this to true ensures that generate will create different fetchlists even without intervening updatedb-s, at the cost of running an additional job to update CrawlDb. If false, running generate twice without intervening updatedb will generate identical fetchlists. See also crawl.gen.delay which defines how long items already generated are blocked. generate.min.score 0 Select only entries with a score larger than generate.min.score. generate.min.interval -1 Select only entries with a retry interval lower than generate.min.interval. A value of -1 disables this check. generate.hostdb Path to HostDB, required for the generate.max.count.expr and generate.fetch.delay.expr properties. See https://issues.apache.org/jira/browse/NUTCH-2368 generate.fetch.delay.expr Controls variable fetcher.server.delay via a Jexl expression and HostDB information. It allows you to alter fetch delay based on HostDB data. See https://issues.apache.org/jira/browse/NUTCH-2368 generate.max.count.expr Controls variable generate.max.count via a Jexl expression and HostDB information. It allows you to alter maxCount based on HostDB data. See https://issues.apache.org/jira/browse/NUTCH-2368 generate.restrict.status Select only entries of this status, see https://issues.apache.org/jira/browse/NUTCH-1248 partition.url.mode byHost Determines how to partition URLs. Default value is 'byHost', also takes 'byDomain' or 'byIP'. crawl.gen.delay 604800000 This value, expressed in milliseconds, defines how long we should keep the lock on records in CrawlDb that were just selected for fetching. If these records are not updated in the meantime, the lock is canceled, i.e. they become eligible for selecting again. Default value of this is 7 days (604800000 ms). If generate.update.crawldb is false the property crawl.gen.delay has no effect. fetcher.server.delay 5.0 The number of seconds the fetcher will delay between successive requests to the same server. Note that this might get overridden by a Crawl-Delay from a robots.txt and is used ONLY if fetcher.threads.per.queue is set to 1. fetcher.server.min.delay 0.0 The minimum number of seconds the fetcher will delay between successive requests to the same server. This value is applicable ONLY if fetcher.threads.per.queue is greater than 1 (i.e. the host blocking is turned off). fetcher.max.crawl.delay 30 If the Crawl-Delay in robots.txt is set to greater than this value (in seconds) then the fetcher will skip this page, generating an error report. If set to -1 the fetcher will never skip such pages and will wait the amount of time retrieved from robots.txt Crawl-Delay, however long that might be. fetcher.min.crawl.delay ${fetcher.server.delay} Minimum Crawl-Delay (in seconds) accepted in robots.txt, even if the robots.txt specifies a shorter delay. By default the minimum Crawl-Delay is set to the value of `fetcher.server.delay` which guarantees that a value set in the robots.txt cannot make the crawler more aggressive than the default configuration. fetcher.threads.fetch 10 The number of FetcherThreads the fetcher should use. This is also determines the maximum number of requests that are made at once (each FetcherThread handles one connection). The total number of threads running in distributed mode will be the number of fetcher threads * number of nodes as fetcher has one map task per node. fetcher.threads.start.delay 10 Delay in milliseconds between starting Fetcher threads to avoid that all threads simultaneously fetch the first pages and cause that DNS or other resources are temporarily exhausted. fetcher.threads.per.queue 1 This number is the maximum number of threads that should be allowed to access a queue at one time. Setting it to a value > 1 will cause the Crawl-Delay value from robots.txt to be ignored and the value of fetcher.server.min.delay to be used as a delay between successive requests to the same server instead of fetcher.server.delay. fetcher.queue.mode byHost Determines how to put URLs into queues. Default value is 'byHost', also takes 'byDomain' or 'byIP'. Crawl delays are implemented on the level of fetcher queues. http.log.exceptions.suppress.stack java.net.UnknownHostException,java.net.NoRouteToHostException Comma-separated list of exceptions not shown with full stack trace in logs of fetcher and HTTP protocol implementations. The logs may shrink in size significantly, e.g., when for a large unrestricted web crawl unknown hosts are logged shortly without full stack trace. The full class name of the exception class (extending Throwable) including the package path must be specified. fetcher.parse false If true, fetcher will parse content. Default is false, which means that a separate parsing step is required after fetching is finished. fetcher.store.content true If true, fetcher will store content. fetcher.signature false If true, fetcher will generate the signature for successfully fetched documents even if the content is not parsed by fetcher (see property fetcher.parse). Default is false, which means that the signature is calculated when parsing either by the fetcher or during the parsing step. Note that a non-parsing fetcher can only generate signatures based on the binary content and not on the textual content. An appropriate signature class should be chosen (see property db.signature.class). fetcher.timelimit.mins -1 This is the number of minutes allocated to the fetching. Once this value is reached, any remaining entry from the input URL list is skipped and all active queues are emptied. The default value of -1 deactivates the time limit. fetcher.max.exceptions.per.queue 5 The maximum number of protocol-level exceptions (e.g. timeouts) or HTTP status codes mapped to ProtocolStatus.EXCEPTION per host (or IP) queue. Once this value is reached, any remaining entries from this queue are purged, effectively stopping the fetching from this host/IP. A value of -1 deactivates this limit. Note that the exponential backoff mechanism (see the property fetcher.exceptions.per.queue.delay) causes increasing wait times after each exception in a queue. If there is no time limit (fetcher.timelimit.mins) or minimum throughput (fetcher.throughput.threshold.pages) configured, it is recommended to set this property to a considerably low value. This avoids the fetch process from hanging when only URLs in blocked queues remain. fetcher.exceptions.per.queue.delay ${fetcher.server.delay} Initial value (in seconds) of an additional dynamic delay slowing down fetches from a queue after an exception has occurred (see also fetcher.max.exceptions.per.queue). Starting with the initial value the delay doubles with every observed exception: delay = fetcher.exceptions.per.queue.delay * 2^num_exception_in_queue An initial value of 0.0 disables this exponential backoff mechanism. fetcher.exceptions.per.queue.clear.after 1800 Time in seconds after which exception counters in queues can be cleared. This happens only if no items are queued in this queue and the configured time span has elapsed in addition to the crawl delay including the exponential backoff time, see fetcher.exceptions.per.queue.delay. fetcher.throughput.threshold.pages -1 The threshold of minimum pages per second. If the fetcher downloads less pages per second than the configured threshold, the fetcher stops, preventing slow queue's from stalling the throughput. This threshold must be an integer. This can be useful when fetcher.timelimit.mins is hard to determine. The default value of -1 disables this check. fetcher.throughput.threshold.retries 5 The number of times the fetcher.throughput.threshold.pages is allowed to be exceeded. This settings prevents accidental slow downs from immediately shutting down the fetcher threads. The throughput is checked approx. every second. Note: the number of retries should be lower than the timeout defined by mapreduce.task.timeout and fetcher.threads.timeout.divisor (see there). For the default values, the timeout is 300 seconds. Consequently, the number of retries should be significantly lower. fetcher.throughput.threshold.check.after 5 The number of minutes after which the throughput check is enabled. fetcher.threads.timeout.divisor 2 (EXPERT) The thread time-out divisor to use. By default threads have a time-out value of mapreduce.task.timeout / 2. Increase this setting if the fetcher waits too long before killing hung threads. Be careful, a too high setting (+8) will most likely kill the fetcher threads prematurely. The fetcher thread time-out avoids that the task timeout (defined by the Hadoop configuration property mapreduce.task.timeout) is reached and the fetcher job is failed. fetcher.queue.depth.multiplier 50 (EXPERT)The fetcher buffers the incoming URLs into queues based on the [host|domain|IP] (see param fetcher.queue.mode). The depth of the queue is the number of threads times the value of this parameter. A large value requires more memory but can improve the performance of the fetch when the order of the URLs in the fetch list is not optimal. fetcher.follow.outlinks.depth -1 (EXPERT)When fetcher.parse is true and this value is greater than 0 the fetcher will extract outlinks and follow until the desired depth is reached. A value of 1 means all generated pages are fetched and their first degree outlinks are fetched and parsed too. Be careful, this feature is in itself agnostic of the state of the CrawlDb and does not know about already fetched pages. A setting larger than 2 will most likely fetch home pages twice in the same fetch cycle. It is highly recommended to set db.ignore.external.links to true to restrict the outlink follower to URLs within the same domain. When disabled (false) the feature is likely to follow duplicates even when depth=1. A value of -1 of 0 disables this feature. fetcher.follow.outlinks.num.links 4 (EXPERT)The number of outlinks to follow when fetcher.follow.outlinks.depth is enabled. Be careful, this can multiply the total number of pages to fetch. This works with fetcher.follow.outlinks.depth.divisor, by default settings the followed outlinks at depth 1 is 8, not 4. fetcher.follow.outlinks.depth.divisor 2 (EXPERT)The divisor of fetcher.follow.outlinks.num.links per fetcher.follow.outlinks.depth. This decreases the number of outlinks to follow by increasing depth. The formula used is: outlinks = floor(divisor / depth * num.links). This prevents exponential growth of the fetch list. fetcher.follow.outlinks.ignore.external true Whether to ignore or follow external links. Set db.ignore.external.links to false and this to true to store outlinks in the output but not follow them. If db.ignore.external.links is true this directive is ignored. fetcher.bandwidth.target -1 Target bandwidth in kilobits per sec for each mapper instance. This is used to adjust the number of fetching threads automatically (up to fetcher.maxNum.threads). A value of -1 deactivates the functionality, in which case the number of fetching threads is fixed (see fetcher.threads.fetch). fetcher.maxNum.threads 25 Max number of fetch threads allowed when using fetcher.bandwidth.target. Defaults to fetcher.threads.fetch if unspecified or set to a value lower than it. fetcher.bandwidth.target.check.everyNSecs 30 (EXPERT) Value in seconds which determines how frequently we should reassess the optimal number of fetch threads when using fetcher.bandwidth.target. Defaults to 30 and must be at least 1. fetcher.store.robotstxt false If true (and fetcher.store.content is also true), fetcher will store the robots.txt response content and status for debugging or archival purposes. The robots.txt is added to the content/ folder of the fetched segment. fetcher.publisher false Set this value to true if you want to use an implementation of the Publisher/Subscriber model. Make sure to set corresponding Publisher implementation specific properties fetcher.filter.urls false Whether fetcher will filter URLs (with the configured URL filters). fetcher.normalize.urls false Whether fetcher will normalize URLs (with the configured URL normalizers). http.redirect.max 0 The maximum number of redirects the fetcher will follow when trying to fetch a page. If set to negative or 0, fetcher won't immediately follow redirected URLs, instead it will record them for later fetching. http.redirect.max.exceeded.skip false Whether to skip the last URL in a redirect chain when when redirects are followed (http.redirect.max > 0) and the maximum number of redirects in a chain is exceeded (redirect_count > http.redirect.max). If not skipped the redirect target URLs are stored as `linked` and fetched in one of the following cycles. See also NUTCH-2748. fetcher.redirect.dedupcache.seconds -1 The maximum time in seconds fetcher will cache redirects for deduplication. If the same redirect URL is seen again withing this time it is skipped. This allows to avoid pathological cases where many or most of the URLs of a host are redirected to the same URL, eg. a page to login, accept cookies, indicating an error. A value less or equal zero disables redirect deduplication. Caveat: This may break setting cookies via recursive redirect chains. fetcher.redirect.dedupcache.size 1000 The maximum size of the cache to deduplicate redirects, see `fetcher.redirect.dedupcache.seconds`. segment.reader.content.recode false SegmentReader when dumping segments: If true try to recode content of HTML documents from the original encoding to UTF-8. Note, this property can be overwritten by SegmentReader command-line options. moreIndexingFilter.indexMimeTypeParts true Determines whether the index-more plugin will split the mime-type in sub parts, this requires the type field to be multi valued. Set to true for backward compatibility. False will not split the mime-type. moreIndexingFilter.mapMimeTypes false Determines whether MIME-type mapping is enabled. It takes a plain text file with mapped MIME-types. With it the user can map both application/xhtml+xml and text/html to the same target MIME-type so it can be treated equally in an index. See conf/contenttype-mapping.txt. moreIndexingFilter.mapMimeTypes.field It's used if moreIndexingFilter.mapMimeTypes is true. Indicates the field where the mapped MIME-type must be written. If it's empty or unset, the content of the field "type" will be replaced by the mapped MIME-type. anchorIndexingFilter.deduplicate false With this enabled the indexer will case-insensitive deduplicate anchors before indexing. This prevents possible hundreds or thousands of identical anchors for a given page to be indexed but will affect the search scoring (i.e. tf=1.0f). indexingfilter.order The order by which index filters are applied. If empty, all available index filters (as dictated by properties plugin-includes and plugin-excludes above) are loaded and applied in system defined order. If not empty, only named filters are loaded and applied in given order. For example, if this property has value: org.apache.nutch.indexer.basic.BasicIndexingFilter org.apache.nutch.indexer.more.MoreIndexingFilter then BasicIndexingFilter is applied first, and MoreIndexingFilter second. Filter ordering might have impact on result if one filter depends on output of another filter. indexer.score.power 0.5 Determines the power of link analyis scores. The boost of each page is set to score<sup>scorePower</sup> where score is its link analysis score and scorePower is the value of this parameter. This is compiled into indexes, so, when this is changed, pages must be re-indexed for it to take effect. indexer.max.title.length 100 The maximum number of characters of a title that are indexed. A value of -1 disables this check. indexer.max.content.length -1 The maximum number of characters of a content that are indexed. Content beyond the limit is truncated. A value of -1 disables this check. indexer.add.domain false Whether to add the domain field to a NutchDocument. indexer.skip.notmodified false Whether the indexer will skip records with a db_notmodified status. indexer.delete.robots.noindex false Whether the indexer will delete documents marked by robots=noindex indexer.delete.skipped.by.indexingfilter false Whether the indexer will delete documents that were skipped by indexing filters indexer.delete false Whether the indexer will delete documents that are gone. Gone pages include redirects and duplicates. See also: 'link.delete.gone'. indexer.indexwriters.file index-writers.xml The configuration file for index writers. exchanges.exchanges.file exchanges.xml The configuration file used by the Exchange component. urlnormalizer.order org.apache.nutch.net.urlnormalizer.basic.BasicURLNormalizer org.apache.nutch.net.urlnormalizer.regex.RegexURLNormalizer Order in which normalizers will run. If any of these isn't activated it will be silently skipped. If other normalizers not on the list are activated, they will run in random order after the ones specified here are run. urlnormalizer.regex.file regex-normalize.xml Name of the config file used by the RegexUrlNormalizer class. urlnormalizer.loop.count 1 Optionally loop through normalizers several times, to make sure that all transformations have been performed. urlnormalizer.basic.host.idn Let urlnormalizer-basic (org.apache.nutch.net.urlnormalizer.basic.BasicURLNormalizer) normalize Internationalized Domain Names (IDNs). Possible values are: `toAscii` - convert the Unicode form to the ASCII (Punycode) representation, `toUnicode` - convert ASCII (Punycode) to Unicode, or if left empty no normalization of IDNs is performed. urlnormalizer.basic.host.idna2008 false If true, let urlnormalizer-basic normalize Internationalized Domain Names (IDNs) using the standard IDNA2008 (RFC 5890). If false, use IDNA2003 (RFC 3490). Note that urlnormalizer.basic.host.idn must be set, otherwise this property has no effect. urlnormalizer.basic.host.trim-trailing-dot false urlnormalizer-basic: Trim a trailing dot in host names: `https://example.org./` is normalized to `https://example.org/`. urlnormalizer.protocols.file protocols.txt urlnormalizer-protocol configuration file urlnormalizer.protocols.rules urlnormalizer-protocol rule definitions: if not empty, takes precedence over rules defined in the rule file (see urlnormalizer.protocols.file) mime.type.magic true Defines if the mime content type detector uses magic resolution. plugin.folders plugins Directories where Nutch plugins are located. Each element may be a relative or absolute path. If absolute, it is used as is. If relative, it is searched for on the classpath. For secure deployments, treat these directories as trusted code: use read-only filesystem permissions or immutable images so untrusted parties cannot add or replace plugin JARs or plugin.xml files. plugin.auto-activation true Defines if some plugins that are not activated regarding the plugin.includes and plugin.excludes properties must be automatically activated if they are needed by some active plugins. plugin.includes protocol-http|urlfilter-regex|parse-(html|tika)|index-(basic|anchor)|indexer-solr|scoring-opic|urlnormalizer-(pass|regex|basic) Regular expression naming plugin directory names to include. Any plugin not matching this expression is excluded. By default Nutch includes plugins to crawl HTML and various other document formats via HTTP/HTTPS and indexing the crawled content into Solr. More plugins are available to support more indexing backends, to fetch ftp:// and file:// URLs, for focused crawling, and many other use cases. plugin.excludes Regular expression naming plugin directory names to exclude. urlmeta.tags To be used in conjunction with features introduced in NUTCH-655, which allows for custom metatags to be injected alongside your crawl URLs. Specifying those custom tags here will allow for their propagation into a pages outlinks, as well as allow for them to be included as part of an index. Values should be comma-delimited. ("tag1,tag2,tag3") Do not pad the tags with white-space at their boundaries, if you are using anything earlier than Hadoop-0.21. parse.plugin.file parse-plugins.xml The name of the file that defines the associations between content-types and parsers. parser.character.encoding.default windows-1252 The character encoding to fall back to when no other information is available encodingdetector.charset.min.confidence -1 A integer between 0-100 indicating minimum confidence value for charset auto-detection. Any negative value disables auto-detection. parser.caching.forbidden.policy content If a site (or a page) requests through its robot metatags that it should not be shown as cached content, apply this policy. Currently three keywords are recognized: "none" ignores any "noarchive" directives. "content" doesn't show the content, but shows summaries (snippets). "all" doesn't show either content or summaries. parser.html.impl neko HTML Parser implementation. Currently the following keywords are recognized: "neko" uses NekoHTML, "tagsoup" uses TagSoup. parser.html.form.use_action false If true, HTML parser will collect URLs from form action attributes. This may lead to undesirable behavior (submitting empty forms during next fetch cycle). If false, form action attribute will be ignored. parser.html.outlinks.ignore_tags Comma separated list of HTML tags, from which outlinks shouldn't be extracted. Nutch takes links from: a, area, form, frame, iframe, script, link, img. If you add any of those tags here, it won't be taken. Default is empty list. Probably reasonable value for most people would be "img,script,link". parser.html.outlinks.htmlnode_metadata_name if not empty, the source nodename of a found outlink will be set in the metadata with this name into the outlink parser.html.line.separators article,aside,blockquote,canvas,dd,div,dl,dt,fieldset,figcaption,figure,footer,form,h1,h2,h3,h4,h5,h6,header,hr,li,main,nav,noscript,ol,output,p,pre,section,table,tfoot,ul,video Comma separated list of HTML tags. Newline will be added to the parsed text after these tages. The default list above are the block-level HTML elements. Tags must be in lower case. To disable this feature, leave the list empty. htmlparsefilter.order The order by which HTMLParse filters are applied. If empty, all available HTMLParse filters (as dictated by properties plugin-includes and plugin-excludes above) are loaded and applied in system defined order. If not empty, only named filters are loaded and applied in given order. HTMLParse filter ordering MAY have an impact on end result, as some filters could rely on the metadata generated by a previous filter. parsefilter.naivebayes.trainfile naivebayes-train.txt Set the name of the file to be used for Naive Bayes training. The format will be: Each line contains two tab separated parts There are two columns/parts: 1. "1" or "0", "1" for relevant and "0" for irrelevant documents. 2. Text (text that will be used for training) Each row will be considered a new "document" for the classifier. CAUTION: Set the parser.timeout to -1 or a bigger value than 30, when using this classifier. parsefilter.naivebayes.wordlist naivebayes-wordlist.txt Put the name of the file you want to be used as a list of important words to be matched in the URL for the model filter. The format should be one word per line. parser.timeout 30 Timeout in seconds for the parsing of a document, otherwise treats it as an exception and moves on the the following documents. This parameter is applied to any Parser implementation. Set to -1 to deactivate, bearing in mind that this could cause the parsing to crash because of a very long or corrupted document. parse.filter.urls true Whether the parser will filter URLs (with the configured URL filters). parse.normalize.urls true Whether the parser will normalize URLs (with the configured URL normalizers). parser.skip.truncated true Boolean value for whether we should skip parsing for truncated documents. By default this property is activated due to extremely high levels of CPU which parsing can sometimes take. parser.delete.failed.parse false Boolean value for whether we should delete a page from the index when parsing the page fails. By default this property is deactivated, because it will delete an existing page from the index, where a previous fetch produced content that was successfully parsed. parser.store.text true If true (default value), parser will store parse text (parse_text directory within the segment). tika.config.file tika-config.xml Nutch-specific Tika config file tika.uppercase.element.names true Determines whether TikaParser should uppercase the element name while generating the DOM for a page, as done by Neko (used per default by parse-html)(see NUTCH-1592). tika.extractor none Which text extraction algorithm to use. Valid values are: boilerpipe or none. tika.extractor.boilerpipe.algorithm ArticleExtractor Which Boilerpipe algorithm to use. Valid values are: DefaultExtractor, ArticleExtractor or CanolaExtractor. tika.extractor.boilerpipe.mime.types text/html,application/xhtml+xml Comma-separated list of MIME types accepted for Boilerpipe extraction, documents of other MIME types are not passed to the Boilerpipe extractor. tika.parse.embedded true Whether parse-tika shall parse embedded documents (even recursively). urlfilter.domain.file domain-urlfilter.txt Name of file on CLASSPATH containing either top level domains or hostnames used by urlfilter-domain (DomainURLFilter) plugin. urlfilter.regex.file regex-urlfilter.txt Name of file on CLASSPATH containing regular expressions used by urlfilter-regex (RegexURLFilter) plugin. urlfilter.automaton.file automaton-urlfilter.txt Name of file on CLASSPATH containing regular expressions used by urlfilter-automaton (AutomatonURLFilter) plugin. urlfilter.prefix.file prefix-urlfilter.txt Name of file on CLASSPATH containing URL prefixes used by urlfilter-prefix (PrefixURLFilter) plugin. urlfilter.suffix.file suffix-urlfilter.txt Name of file on CLASSPATH containing URL suffixes used by urlfilter-suffix (SuffixURLFilter) plugin. urlfilter.fast.file fast-urlfilter.txt Name of file containing rules and regular expressions used by urlfilter-fast (FastURLFilter) plugin. If the filename includes a scheme (for example, hdfs://) it is loaded using the Hadoop FileSystem implementation supporting that scheme. If the filename does not contain a scheme, the file is loaded from CLASSPATH. If indicated by file extension (.gz, .bzip2, .zst), the file is decompressed while reading using Hadoop-provided compression codecs. urlfilter.fast.url.max.length -1 Filters URLs based on their overall length. The default value of -1 means that it is deactivated. urlfilter.fast.url.path.max.length -1 Filters URLs based on the length of their path element. The default value of -1 means that it is deactivated. urlfilter.fast.url.query.max.length -1 Filters URLs based on the length of their query element. The default value of -1 means that it is deactivated. urlfilter.order The order by which URL filters are applied. If empty, all available URL filters (as dictated by properties plugin-includes and plugin-excludes above) are loaded and applied in system defined order. If not empty, only named filters are loaded and applied in given order. For example, if this property has value: org.apache.nutch.urlfilter.regex.RegexURLFilter org.apache.nutch.urlfilter.prefix.PrefixURLFilter then RegexURLFilter is applied first, and PrefixURLFilter second. Since all filters are AND'ed, filter ordering does not have impact on end result, but it may have performance implication, depending on relative expensiveness of filters. scoring.filter.order The order in which scoring filters are applied. This may be left empty (in which case all available scoring filters will be applied in system defined order), or a space separated list of implementation classes. scoring.depth.max 1000 Max depth value from seed allowed by default. Can be overridden on a per-seed basis by specifying "_maxdepth_=VALUE" as a seed metadata. This plugin adds a "_depth_" metadatum to the pages to track the distance from the seed it was found from. The depth is used to prioritise URLs in the generation step so that shallower pages are fetched first. scoring.depth.override.pattern URLs matching this pattern pass a different max depth value to their outlinks configured in scoring.depth.max.override. scoring.depth.max.override This max depth value is passed to outlinks matching the pattern configured in scoring.depth.override.pattern. scoring.similarity.model cosine The type of similarity metric to use. Eg - cosine (which is, currently, the only available model). Please make sure to set the model specific properties for the scoring to function properly. Description of these properties can be found on the wiki. scoring.similarity.ngrams 1,1 Specifies the min 'n' and max 'n' in ngrams as comma-separated. If one value is specified as 'n', it will be used for both the min 'n' and max 'n' in ngrams. cosine.goldstandard.file goldstandard.txt Path to the gold standard file which contains all the relevant text and terms, pertaining to the domain. scoring.similarity.stopword.file stopwords.txt Name of the stopword text file. The user can specify a custom list of stop words in a text file. Each new stopword should be on a new line. scoring.orphan.mark.gone.after 2592000 Time in seconds after which orphaned pages are marked as gone. Default is 30 days. scoring.orphan.mark.orphan.after 3456000 Time in seconds after which orphaned pages are marked as gone. Default is 40 days. scoring.db.md Comma-separated list of keys to be taken from CrawlDb metadata of a URL to the fetched content metadata. scoring.content.md Comma-separated list of keys to be taken from content metadata of a URL and put as metadata in the parse data. scoring.parse.md Comma-separated list of keys to be taken from metadata of the parse data of a URL and propagated as metadata to the URL outlinks. lang.analyze.max.length 2048 The maximum number of bytes used to identify the language (0 means full content analysis). The larger is this value, the better is the analysis, but the slowest it is. lang.extraction.policy detect,identify This determines when the plugin uses detection and statistical identification mechanisms. The order in which the detect and identify are written will determine the extraction policy. Default case (detect,identify) means the plugin will first try to extract language info from page headers and metadata, if this is not successful it will try using tika language identification. Possible values are: detect identify detect,identify identify,detect lang.identification.only.certain false If set to true with lang.extraction.policy containing identify, the language code returned by Tika will be assigned to the document ONLY if it is deemed certain by Tika. lang.index.languages If not empty, should be a comma separated list of language codes. Only documents with one of these language codes will be indexed. "unknown" is a valid language code, will match documents where language detection failed. index.jexl.filter A JEXL expression. If it evaluates to false, the document will not be indexed. Available primitives in the JEXL context: * status, fetchTime, modifiedTime, retries, interval, score, signature, url, text, title Available objects in the JEXL context: * httpStatus - contains majorCode, minorCode, message * documentMeta, contentMeta, parseMeta - contain all the Metadata properties. each property value is always an array of Strings (so if you expect one value, use [0]) * doc - contains all the NutchFields from the NutchDocument. each property value is always an array of Objects. Expressions are evaluated in a sandboxed JEXL engine (see also nutch.jexl.disable.sandbox). nutch.jexl.disable.sandbox false If true, disables the Commons JEXL sandbox and the restriction on the JEXL "new" operator for all Nutch JEXL expressions (index filter, generator, hostdb filter, crawl_db_reader, exchange-jexl, etc.). This is unsafe and should only be used in fully trusted environments when a legitimate expression cannot be expressed under the default sandbox. index.static Used by plugin index-static to adds fields with static data at indexing time. You can specify a comma-separated list of fieldname:fieldcontent per Nutch job. Each fieldcontent can have multiple values separated by space, e.g., field1:value1.1 value1.2 value1.3,field2:value2.1 value2.2 ... It can be useful when collections can't be created by URL patterns, like in subcollection, but on a job-basis. index.static.fieldsep , Used by plugin index-static to parse the property index.static. Default: comma. This delimiter is used to separate individual field specifications in the property. index.static.keysep : Used by plugin index-static to parse the property index.static. Default: colon. This delimiter is used to separate the field name from the field value in the field specification. index.static.valuesep Used by plugin index-static to parse the property index.static. Default: space. This delimiter is used to separate multiple field values in the value setting of the field specification. index.parse.md metatag.description,metatag.keywords Comma-separated list of keys to be taken from the parse metadata to generate fields. Can be used e.g. for 'description' or 'keywords' provided that these values are generated by a parser (see parse-metatags plugin) index.content.md Comma-separated list of keys to be taken from the content metadata to generate fields. index.db.md Comma-separated list of keys to be taken from the CrawlDb metadata to generate fields. Can be used to index values propagated from the seeds with the plugin urlmeta index.metadata.separator Separator to use if you want to index multiple values for a given field. Leave empty to treat each value as a single value. index.geoip.db.anonymous GeoIP2 Anonymous IP database file (MMDB format). Identifies anonymous proxies, VPNs, Tor exit nodes, and hosting providers. index.geoip.db.asn GeoIP2/GeoLite2 ASN database file (MMDB format). Provides autonomous system number and organization information. index.geoip.db.city GeoIP2/GeoLite2 City database file (MMDB format). Provides city, subdivision, country, continent, and location data. index.geoip.db.connection GeoIP2 Connection Type database file (MMDB format). Identifies connection type: Cable/DSL, Cellular, Corporate, or Satellite. index.geoip.db.country GeoIP2/GeoLite2 Country database file (MMDB format). Provides country, continent, and represented country information. This is a lighter-weight alternative to the City database when only country-level information is needed. index.geoip.db.domain GeoIP2 Domain database file (MMDB format). Provides the second-level domain associated with the IP address. index.geoip.db.isp GeoIP2 ISP database file (MMDB format). Provides ISP, organization, and autonomous system information. index.geoip.insights.userid The userId for the MaxMind GeoIP2 Precision Insights web service. If set along with licensekey, the Insights service will be queried in addition to any configured local databases. index.geoip.insights.licensekey The license key for the MaxMind GeoIP2 Precision Insights web service. index.replace.regexp Allows indexing-time regexp replace manipulation of metadata fields. The format of the property is a list of regexp replacements, one line per field being modified. Include index-replace in your plugin.includes. Example: hostmatch=.*somedomain.com fldname1=/regexp/replacement/flags fldname2=/regexp/replacement/flags Field names would be one of those from https://cwiki.apache.org/confluence/display/NUTCH/IndexStructure See https://cwiki.apache.org/confluence/display/NUTCH/IndexReplace for further details. index.arbitrary.function.count The count of arbitrary additions/edits to the document. Specify the remaining properties (fieldName, className, constructorArgs, methodName, and methodArgs) independently in this file by appending a dot (.) followed by integer numerals (beginning with '0') to the property names, e.g.: index.arbitrary.fieldName.0 for the field to add/set with the first arbitrary addition or: index.arbitrary.className.3 for the POJO class name to use in setting the fourth arbitrary addition. index.arbitrary.fieldName.0 The name of the field to add to the document with the value returned from the custom POJO. index.arbitrary.className.0 The fully qualified name of the POJO class that will supply values for the new field. index.arbitrary.constructorArgs.0 The values (as strings) to pass into the POJO constructor. The POJO must accept a String representation of the NutchDocument's URL as the first parameter in the constructor. The values you specify here will populate the constructor arguments 1,..,n-1 where n=the count of arguments to the constructor. Argument #0 will be the NutchDocument's URL. index.arbitrary.methodName.0 The name of the method to invoke on the instance of your custom class in order to determine the value to add to the document. index.arbitrary.methodArgs.0 The values (as strings) to pass into the named method on the POJO instance. Unlike the constructor args, there is no required argument that this method in the POJO must accept, i.e., the Arbitrary Indexer doesn't supply any arguments taken from the NutchDocument values by default. index.arbitrary.overwrite.0 Whether to overwrite any existing value in the doc for for fieldName. Default is false if not specified in config index.arbitrary.all.fields.access.0 Whether to pass all indexing filter fields to constructor for the user POJO. These are the NutchDocument doc, Parse parse, url (as org.apache.hadoop.io.Text), CrawlDatum datum, and Inlinks inlinks objects. Default value is false to preserve compatibility with previous index-arbitrary behavior. metatags.names description,keywords Names of the metatags to extract, separated by ','. Use '*' to extract all metatags. Prefixes the names with 'metatag.' in the parse-metadata. For instance to index description and keywords, you need to activate the plugin index-metadata and set the value of the parameter 'index.parse.md' to 'metatag.description,metatag.keywords'. io.serializations org.apache.hadoop.io.serializer.WritableSerialization,org.apache.hadoop.io.serializer.JavaSerialization A list of serialization classes that can be used for obtaining serializers and deserializers. link.ignore.internal.host true Ignore outlinks to the same hostname. link.ignore.internal.domain true Ignore outlinks to the same domain. link.ignore.limit.page true Limit to only a single outlink to the same page. link.ignore.limit.domain true Limit to only a single outlink to the same domain. link.analyze.num.iterations 10 The number of LinkRank iterations to run. link.analyze.initial.score 1.0f The initial score. link.analyze.damping.factor 0.85f The damping factor. link.delete.gone false Whether to delete gone pages from the web graph. Gone pages include redirects and duplicates. link.score.updater.clear.score 0.0f The default score for URLs that are not in the web graph. mapreduce.fileoutputcommitter.marksuccessfuljobs false Hadoop >= 0.21 generates SUCCESS files in the output which can crash the readers. This should not be an issue once Nutch is ported to the new MapReduce API but for now this parameter should prevent such cases. subcollection.default.fieldname subcollection The default field name for the subcollections. subcollection.case.insensitive false Whether the URL prefixes are to be treated case insensitive. headings h1,h2 Comma separated list of headings to retrieve from the document headings.multivalued false Whether to support multivalued headings. mimetype.filter.file mimetype-filter.txt The configuration file for the mimetype-filter plugin. This file contains the rules used to allow or deny the indexing of certain documents. page.load.delay 3 The delay in seconds to use when loading a page with htmlunit or selenium. take.screenshot false Boolean property determining whether the protocol-htmlunit WebDriver should capture a screenshot of the URL. If set to true remember to define the 'screenshot.location' property as this determines the location screenshots should be persisted to on HDFS. If that property is not set, screenshots are simply discarded. screenshot.location The location on disk where a URL screenshot should be saved to if the 'take.screenshot' property is set to true. By default this is null, in this case screenshots held in memory are simply discarded. htmlunit.enable.javascript true A Boolean value representing if javascript should be enabled or disabled when using htmlunit. The default value is enabled. htmlunit.javascript.timeout 3500 The timeout in milliseconds when loading javascript with lib-htmlunit. This setting is used by protocol-htmlunit since they depending on lib-htmlunit for fetching. htmlunit.enable.css false A Boolean value representing if CSS should be enabled or disabled when using htmlunit. The default value is disabled. selenium.driver firefox A String value representing the flavour of Selenium WebDriver() to use. Currently the following options exist - 'firefox', 'chrome', 'safari', 'opera' and 'remote'. If 'remote' is used it is essential to also set correct properties for 'selenium.hub.port', 'selenium.hub.path', 'selenium.hub.host', 'selenium.hub.protocol', 'selenium.grid.driver', 'selenium.grid.binary' and 'selenium.enable.headless'. selenium.hub.port 4444 Selenium Hub Location connection port selenium.hub.path /wd/hub Selenium Hub Location connection path selenium.hub.host localhost Selenium Hub Location connection host selenium.hub.protocol http Selenium Hub Location connection protocol selenium.grid.driver firefox A String value representing the flavour of Selenium WebDriver() used on the selenium grid. We must set `selenium.driver` to `remote` first. Currently the following options exist - 'firefox', 'chrome', 'random' selenium.grid.binary A String value representing the path to the browser binary location for each node selenium.enable.headless false A Boolean value representing the headless option for Firefix and Chrome drivers selenium.firefox.allowed.hosts localhost A String value representing the allowed hosts preference according to the operating system hosts file (Example - /etc/hosts in Unix). Currently this option exist for - 'firefox' selenium.firefox.binary.timeout 45 A Long value representing the timeout value for firefox to be available for command execution. The value is in seconds. Currently this option exist for - 'firefox' selenium.firefox.enable.flash false A Boolean value representing if flash should be enabled or disabled. The default value is disabled. Currently this option exist for - 'firefox' selenium.firefox.load.image 1 An Integer value representing the restriction on loading images. The default value is no restriction i.e. load all images. Other options are: 1: Load all images, regardless of origin 2: Block all images 3: Prevent third-party images from loading Currently this option exist for - 'firefox' selenium.firefox.load.stylesheet 1 An Integer value representing the restriction on loading stylesheet. The default value is no restriction i.e. load all stylesheet. Other options are: 1: Load all stylesheet 2: Block all stylesheet Currently this option exist for - 'firefox' webdriver.chrome.driver /root/chromedriver The path to the ChromeDriver binary interactiveselenium.handlers DefaultHandler A comma separated list of Selenium handlers that should be run for a given URL. The DefaultHandler causes the same functionality as protocol-selenium. Custom handlers can be implemented in the plugin package and included here. store.ip.address false Enables us to capture the specific IP address (InetSocketAddress) of the host which we connect to via the given protocol. Currently supported by: protocol-ftp, protocol-http, protocol-okhttp, protocol-htmlunit, protocol-selenium. Note that the IP address is required by the plugin index-geoip and when writing WARC files. store.http.request false Store the HTTP request headers sent by Nutch. Useful for debugging and required when writing WARC files. store.http.headers false Store the HTTP response headers received by Nutch from the server. Useful for debugging and required when writing WARC files. store.protocol.versions false Store protocol versions in response metadata: HTTP and SSL/TLS versions, SSL/TTL cipher suites and related information depending on the protocol implementation. Supported by: protocol-okhttp. index.links.outlinks.host.ignore false Ignore outlinks that point out to the same host as the URL being indexed. By default all outlinks are indexed. If db.ignore.internal.links is true (default value), this setting does nothing since the internal links are already ignored. index.links.inlinks.host.ignore false Ignore inlinks coming from the same host as the URL being indexed. By default all inlinks are indexed. If db.ignore.internal.links is true (default value), this setting does nothing since the internal links are already ignored. index.links.hosts.only false This force the index-links plugin to only index the host portion of the inlinks or outlinks. hostdb.recheck.interval 86400000 Interval between rechecks in milliseconds. Default is one week. Recheck interval is multiplied by the number of DNS lookup failures for a given host. hostdb.purge.failed.hosts.threshold 3 If hosts have more failed DNS lookups than this threshold, they are removed from the HostDB. Hosts can, of course, return if they are still present in the CrawlDb. hostdb.num.resolvers.threads 25 Number of resolver threads per reducer. Make sure your DNS resolver is capable of handling this value multiplied by the number of reducers. hostdb.check.failed true True if hosts for which DNS lookup failed are eligible for recheck. If false, hosts that failed DNS lookup more than 0 times are not eligible for DNS lookup. hostdb.check.new true True if newly discovered hosts eligible for DNS lookup check. If false, hosts that are just added to the HostDB are not eligible for DNS lookup. hostdb.check.known true True if newly already known hosts eligible for DNS lookup check. If false, known hosts are not eligible for DNS lookup. hostdb.force.check false If true hosts are checked regardless of their respective recheck intervals or status. hostdb.url.filter false Whether the records are to be passed through configured filters. hostdb.url.normalize false Whether the records are to be passed through configured normalizers. hostdb.numeric.fields _rs_ Comma-separated list of CrawlDatum metadata fields for which aggregations are needed. hostdb.string.fields Content-Type Comma-separated list of CrawlDatum metadata fields for which sums are needed. hostdb.percentiles 50,75,95,99 Comma-separated list of percentiles that must be calculated for all numeric field aggregations. Host metadata will contain fields for each percentile. hostdb.crawldatum.processors Comma-separated list of custom per-host statistic aggregators. Aggregator classes must implement the interface org.apache.nutch.hostdb.CrawlDatumProcessor and are called during HostDB construction. publisher.order The order in which the publisher queues would be loaded. If empty, all available publishers (see properties plugin-includes and plugin-excludes) are loaded and applied in system defined order. If not empty, only named publishers are loaded and applied in the given order. rabbitmq.publisher.server.uri amqp://localhost:5672/ URI with connection parameters in the form amqp://hostname:port/virtualHost or amqp://username:password@hostname:port/virtualHost where: username is the username for RabbitMQ server. password is the password for RabbitMQ server. hostname is where the RabbitMQ server is running. port is where the RabbitMQ server is listening. virtualHost is where where the exchange is and the user has access. A typical local RabbitMQ broker uses the well-known guest/guest account; include username:password@ in the URI when required. rabbitmq.publisher.binding false Whether the relationship between an exchange and a queue is created automatically. Default "false". NOTE: Binding between exchanges is not supported. rabbitmq.publisher.binding.arguments Arguments used in binding. It must have the form key1=value1,key2=value2. This value is only used when the exchange's type is headers and the value of 'rabbitmq.publisher.binding' property is true. In other cases is ignored. rabbitmq.publisher.exchange.name Name for the exchange where the messages will be sent. Default "". rabbitmq.publisher.exchange.options type=direct,durable=true Options used when the exchange is created. Only used when the value of 'rabbitmq.publisher.binding' property is true. Default "type=direct,durable=true". rabbitmq.publisher.queue.name nutch.events.queue Name of the queue used to create the binding. Default "nutch.queue". Only used when the value of 'rabbitmq.publisher.binding' property is true. rabbitmq.publisher.queue.options durable=true,exclusive=false,auto-delete=false Options used when the queue is created. Only used when the value of 'rabbitmq.publisher.binding' property is true. Default "durable=true,exclusive=false,auto-delete=false". It must have the form durable={durable},exclusive={exclusive},auto-delete={auto-delete},arguments={arguments} where: durable is true or false exclusive is true or false auto-delete is true or false arguments must be the for {key1:value1;key2:value2} rabbitmq.publisher.routingkey The routing key used to publish messages to specific queues. It is only used when the exchange type is "topic" or "direct". Default is the value of 'rabbitmq.publisher.queue.name' property. rabbitmq.publisher.headers.static Headers to add to each message. It must have the form key1=value1,key2=value2. sitemap.strict.parsing true If true (default) the Sitemap parser rejects URLs not sharing the same prefix with the sitemap: a sitemap `http://example.com/catalog/sitemap.xml' may only contain URLs starting with `http://example.com/catalog/'. All other URLs are skipped. If false the parser will allow any URLs contained in the sitemap. sitemap.url.filter true Filter URLs from sitemaps. sitemap.url.normalize true Normalize URLs from sitemaps. sitemap.url.default.sitemap.xml true Always try <host>/sitemap.xml root even if no sitemap is announced in /robots.txt. sitemap.url.overwrite.existing false If true, the record's existing modified time, interval and score are overwritten by the information in the sitemap. WARNING: overwriting these values may have unexpected effects on what is crawled. Use this only if you can trust the sitemap and if the values in the sitemap do fit with your crawler configuration. sitemap.redir.max 3 Maximum number of redirects to follow. sitemap.size.max 52428800 Maximum sitemap size in bytes.