REC_CONTROL(1) PowerDNS Recursor REC_CONTROL(1)

rec_control - Command line tool to control a running Recursor

rec_control [OPTION]... COMMAND [COMMAND-OPTION]...

rec_control allows the operator to query and control a running instance of the PowerDNS Recursor.

rec_control talks to the recursor via a the 'controlsocket'. Which is usually located in /var/run . The --socket-dir or the --config-dir and --config-name switches control to which process rec_control connects.

To see if the Recursor is alive, run:

# rec_control ping

To stop the recursor by hand, run:

# rec_control quit

To dump the cache to disk, execute:

# rec_control dump-cache /tmp/the-cache

NOTE:

Before version 4.5.0, for each command that writes to a file, pdns_recursor would open the file to write to. Starting with 4.5.0, the files are opened by the rec_control command itself using the credentials and the current working directory of the user running rec_control. A single minus - can be used as a filename to write the data to the standard output stream.

provide this helpful message.
Directory where the recursor.conf lives.
Name of the virtual configuration.
Where the controlsocket will live, please use --config-dir instead.
When running in SMP mode, pid of pdns_recursor to control.
Number of seconds to wait for the remote PowerDNS Recursor to respond.

Add names for nameserver domains that may not be throttled.
Add netmasks for nameservers that may not be throttled.
Add a Negative Trust Anchor for DOMAIN, suffixed optionally with REASON.
Add a Trust Anchor for DOMAIN with DS record data DSRECORD. This adds the new Trust Anchor to the existing set of Trust Anchors for DOMAIN.
Shows the currently active queries.
Remove names that are not allowed to be throttled. If NAME is *, remove all
Remove netmasks that are not allowed to be throttled. If NETMASK is *, remove all
Remove Negative Trust Anchor for one or more DOMAINs. Set domain to * to remove all NTA's.
Remove Trust Anchor for one or more DOMAINs. Note that removing the root trust anchor is not possible.
Dumps the entire cache to FILENAME. This file should not exist already, PowerDNS will refuse to overwrite it. While dumping, the recursor might not answer questions.

Typical PowerDNS Recursors run multiple threads, therefore you'll see duplicate, different entries for the same domains. The negative cache is also dumped to the same file. The per-thread positive and negative cache dumps are separated with an appropriate comment.

Dump the contents of the DoT probe map to the FILENAME mentioned.
Dumps the EDNS status to the filename mentioned. This file should not exist already, PowerDNS will refuse to overwrite it. While dumping, the recursor will not answer questions.
Dump the contents of the failed server map to the FILENAME mentioned. This file should not exist already, PowerDNS will refuse to overwrite it otherwise. While dumping, the recursor will not answer questions.
Dump the contents of the map of nameserver names that did not resolve to an address. This file should not exist already, PowerDNS will refuse to overwrite it otherwise. While dumping, the recursor will not answer questions.
Dumps the nameserver speed statistics to the FILENAME mentioned. This file should not exist already, PowerDNS will refuse to overwrite it. While dumping, the recursor will not answer questions. Statistics are kept per thread, and the dumps end up in the same file.
Dumps the content of the RPZ zone named ZONE NAME to the FILENAME mentioned. This file should not exist already, PowerDNS will refuse to overwrite it otherwise. While dumping, the recursor will not answer questions. For details on how RPZ are named see https://docs.powerdns.com/recursor/lua-config/rpz.html#policyname.
Dump the entries of the map containing saved parent NS sets that were successfully used in resolving. The total number of entries is also printed in the header. An entry is saved if the recursor sees that the parent set includes names not in the child set. This is an indication of a misconfigured domain.
Dump the contents of the throttle map to the FILENAME mentioned. This file should not exist already, PowerDNS will refuse to overwrite it otherwise. While dumping, the recursor will not answer questions.
Retrieve a statistic. For items that can be queried, see https://docs.powerdns.com/recursor/metrics.html.
Retrieve all known statistics.
Get the list of names that are not allowed to be throttled.
Get the list of netmasks that are not allowed to be throttled.
Get a list of the currently configured Negative Trust Anchors.
Get a list of the currently configured Trust Anchors.
Retrieves the specified configuration parameter(s).
Get the list of proxy-mapped subnets and associated counters.
Retrieves QType statistics. Queries from cache aren't being counted yet.
Retrieves the remote logger statistics, per type and address.
Asks for a password then returns the hashed and salted version, to use as a webserver password or API key. This command does not contact the recursor but does the hashing inside rec_control. An optional scrypt work factor can be specified, in power of two. The default is 1024.
Shows a list of supported commands understood by the running pdns_recursor
List supported (and potentially disabled) DNSSEC algorithms.
Check if server is alive.
Request shutdown of the recursor, exiting the process while letting the OS clean up resources.
quit-nicely
Request nice shutdown of the recursor. This method allows all threads to finish their current work and releases resources before exiting. This is the preferred method to stop the recursor.
Reloads ACLs.
(Re)loads Lua script FILENAME. If FILENAME is empty, attempt to reload the currently loaded script. This replaces the script currently loaded.
(Re)loads Lua configuration FILENAME. If FILENAME is empty, attempt to reload the currently loaded file. Note that FILENAME will be fully executed, any settings changed at runtime that are not modified in this file, will still be active. The effects of reloading do not always take place immediately, as some subsystems reload and replace configuration in an asynchronous way.
Reload authoritative and forward zones. Retains current configuration in case of errors.
Set the carbon-server setting to CARBON SERVER. If CARBON OURNAME is not empty, also set the carbon-ourname setting to CARBON OURNAME.
Set dnssec-log-bogus setting to SETTING. Set to on or yes to log DNSSEC validation failures and to no or off to disable logging these failures.
Set ecs-minimum-ttl-override to NUM.
Change the maximum number of entries in the NSEC aggressive cache. If the cache is disabled by setting its size to 0 in the config, the cache size cannot be set by this command. Setting the size to 0 by this command still keeps the cache, but makes it mostly ineffective as it is emptied periodically.
Change the maximum number of entries in the DNS cache. If reduced, the cache size will start shrinking to this number as part of the normal cache purging process, which might take a while.
Change the maximum number of entries in the packet cache. If reduced, the cache size will start shrinking to this number as part of the normal cache purging process, which might take a while.
Set minimum-ttl-override to NUM.
Set logging of event trace messages, 0 = disabled, 1 = protobuf, 2 = log file, 3 = protobuf and log file.
Show Yaml representation of odl-style config.
Shows the top-20 queries. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 queries grouped by public suffix list. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 remote hosts causing large answers. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 most active remote hosts. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 queries causing servfail responses. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 queries causing bogus responses. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 queries causing servfail responses grouped by public suffix list. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 queries causing bogus responses grouped by public suffix list. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 most active remote hosts causing servfail responses. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 most active remote hosts causing bogus responses. Statistics are over the last 'stats-ringbuffer-entries' queries.
Shows the top-20 most active downstream timeout destinations. Statistics are over the last 'stats-ringbuffer-entries' queries.
Emit resolution trace for matching queries. No arguments disables tracing. Before version 4.9.0, there was no FILE argument, traces were always written to the log. Starting with version 4.9.0, trace information is written to the file specified, which may be - for the standard out stream.

Queries matching this regular expression will generate voluminous tracing output. Be aware that matches from the packet cache will still not generate tracing. To unset the regex, pass trace-regex without a new regex.

The regular expression is matched against domain queries terminated with a dot. For example the regex 'powerdns.com$' will not match a query for 'www.powerdns.com', since the attempted match will be with 'www.powerdns.com.'.

In addition, since this is a regular expression, to exclusively match queries for 'www.powerdns.com', one should escape the dots: '^www\.powerdns\.com\.$'. Note that the single quotes prevent further interpretation of the backslashes by the shell.

Multiple matches can be chained with the | operator. For example, to match all queries for Dutch (.nl) and German (.de) domain names, use: '\.nl\.$|\.de\.$'.

Unloads Lua script if one was loaded.
Report running version.
Wipe entries for DOMAIN (exact name match) from the cache. This is useful if, for example, an important server has a new IP address, but the TTL has not yet expired. Multiple domain names can be passed. DOMAIN can be suffixed with a $. to delete the whole tree from the cache. i.e. powerdns.com$ will remove all cached entries under and including the powerdns.com name.

Note: this command also wipes the negative cache.

Warning: Don't just wipe "www.somedomain.com", its NS records or CNAME target may still be undesired, so wipe "somedomain.com" as well.

Same as wipe-cache, but only wipe records of type qtype.

pdns_recursor(1) https://docs.powerdns.com/recursor

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PowerDNS.COM BV

November 4, 2024