9.1.3/9.2.1 onwards slow indexer/receiver detection capability is fully functional now (SPL-248188, SPL-248140).   https://docs.splunk.com/Documentation/Splunk/9.2.1/ReleaseNotes/Fixedissues You can enable it on forwarding side in outputs.conf maxSendQSize = <integer> * The size of the tcpout client send buffer, in bytes. If tcpout client(indexer/receiver connection) send buffer is full, a new indexer is randomly selected from the list of indexers provided in the server setting of the target group stanza. * This setting allows forwarder to switch to new indexer/receiver if current indexer/receiver is slow. * A non-zero value means that max send buffer size is set. * 0 means no limit on max send buffer size. * Default: 0 Additionally 9.1.3/9.2.1 and above will correctly log target ipaddress causing tcpout blocking.   WARN AutoLoadBalancedConnectionStrategy [xxxx TcpOutEloop] - Current dest host connection nn.nn.nn.nnn:9997, oneTimeClient=0, _events.size()=20, _refCount=2, _waitingAckQ.size()=4, _supportsACK=1, _lastHBRecvTime=Thu Jan 20 11:07:43 2024 is using 20214400 bytes. Total tcpout queue size is 26214400. Warningcount=20   Note: This config works correctly starting 9.1.3/9.2.1. Do not use it with 9.2.0/9.1.0/9.1.1/9.1.2( there is incorrect calculation https://community.splunk.com/t5/Getting-Data-In/Current-dest-host-connection-is-using-18446603427033668018-bytes/m-p/678842#M113450). ... View more

During graceful indexer/HF restart/stop (basically where ever splunktcp is configured) if you see last entries in metrics.log before splunk finally stops.  Where splunktcpin queue (name=splunktcpin) shows current_size, largest_size, smallest_size has same value( but parsingqueue to indexqueue none blocked), TcpInputProcessor fails to drain splunktcpin queue despite parsingqueue or indexqueue are empty.    02-18-2024 00:54:28.370 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1507, largest_size=1507, smallest_size=1507 02-18-2024 00:54:28.370 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=indexqueue, max_size_kb=10240, current_size_kb=7, current_size=40, largest_size=40, smallest_size=0 02-18-2024 00:54:28.368 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1148, largest_size=1148, smallest_size=1148 02-18-2024 00:54:28.368 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=indexqueue, max_size_kb=10240, current_size_kb=7, current_size=40, largest_size=40, smallest_size=0 02-18-2024 00:53:57.364 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1507, largest_size=1507, smallest_size=1507 02-18-2024 00:53:57.364 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:53:57.362 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1148, largest_size=1148, smallest_size=1148 02-18-2024 00:53:57.362 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:53:26.372 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1507, largest_size=1507, smallest_size=1507 02-18-2024 00:53:26.372 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:53:26.370 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1148, largest_size=1148, smallest_size=1148 02-18-2024 00:53:26.370 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:52:55.371 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1507, largest_size=1507, smallest_size=0 02-18-2024 00:52:55.371 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:52:55.369 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=splunktcpin, blocked=true, max_size_kb=500, current_size_kb=499, current_size=1148, largest_size=1148, smallest_size=0 02-18-2024 00:52:55.369 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:52:24.397 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=splunktcpin, max_size_kb=500, current_size_kb=0, current_size=0, largest_size=30, smallest_size=0 02-18-2024 00:52:24.396 +0000 INFO Metrics - group=queue, ingest_pipe=1, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0 02-18-2024 00:52:24.380 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=splunktcpin, max_size_kb=500, current_size_kb=0, current_size=0, largest_size=16, smallest_size=0 02-18-2024 00:52:24.380 +0000 INFO Metrics - group=queue, ingest_pipe=0, name=indexqueue, max_size_kb=10240, current_size_kb=0, current_size=0, largest_size=1, smallest_size=0   During graceful shutdown pipeline processors are expected to drain the queue. This issue is fixed in 9.2.1 and 9.1.4.  ... View more

There is a practice of setting queueSize in inputs.conf [http://<token>] stanza. queueSize over writes server.conf stanza     [queue=httpInputQ] maxSize   Now if you have multiple tokens with different queueSize.     inputs.conf [http://1] queueSize=1 [http://2] queueSize=2 [http://3] queueSize=3 [http://4] queueSize=4     Globally only one inputs.conf stanza wins for final httpInputQ size. This setting should only be set if setting 'persistentQueueSize' as well. If there are multiple http inputs configured and each input has set 'queueSize' but persistentQueueSize is not is set, splunkd will create one in-memory queue and pick the 'queueSize' value from first stanza after sorting http stanzas with matching token of first received http event in ascending order. With multiple pipelines configured, each pipeline will create one in-memory queue depending on the first http event received by the pipeline thus each pipeline might have different sized httpInputQ created. If there are multiple http stanzas configured and 'persistentQueueSize' is not set, prefer to set 'maxSize' under 'queue=httpInputQ' stanza in server.conf. So best practice would be to never set per token queueSize in inputs.conf. Instead set one time in server.conf, if not setting persistentQueueSize.     [queue=httpInputQ] maxSize     ... View more

Heavy forwarder or indexer crashes with FATAL error on typing thread.   Note: Issue is now fixed for next 9.2.2/9.1.5/9.0.10 patches   Crashing thread: typing_0 Backtrace (PIC build): [0x00007F192F4C2ACF] gsignal + 271 (libc.so.6 + 0x4EACF) [0x00007F192F495EA5] abort + 295 (libc.so.6 + 0x21EA5) [0x000055E24388D6C0] ? (splunkd + 0x1A366C0) [0x000055E24388D770] ? (splunkd + 0x1A36770) [0x000055E2445D6D24] PipelineInputChannelReference::PipelineInputChannelReference(Str const**, PipelineInputChannelSet*, bool) + 388 (splunkd + 0x277FD24) [0x000055E2445BACC3] PipelineData::set_channel(Str const*, Str const*, Str const*) + 243 (splunkd + 0x2763CC3) [0x000055E2445BAF9E] PipelineData::recomputeConfKey(PipelineSet*, bool) + 286 (splunkd + 0x2763F9E) [0x000055E243E3689E] RegexExtractionProcessor::each(CowPipelineData&, PipelineDataVector*, bool) + 718 (splunkd + 0x1FDF89E) [0x000055E243E36BF3] RegexExtractionProcessor::executeMulti(PipelineDataVector&, PipelineDataVector*) + 67 (splunkd + 0x1FDFBF3) [0x000055E243BCD5F2] Pipeline::main() + 1074 (splunkd + 0x1D765F2) [0x000055E244C336FD] Thread::_callMainAndDiscardTerminateException() + 13 (splunkd + 0x2DDC6FD) [0x000055E244C345F2] Thread::callMain(void*) + 178 (splunkd + 0x2DDD5F2) [0x00007F192FF1F1CA] ? (libpthread.so.0 + 0x81CA) [0x00007F192F4ADE73] clone + 67 (libc.so.6 + 0x39E73)                   Crashing thread: typing_0 Backtrace (PIC build): [0x00007F192F4C2ACF] gsignal + 271 (libc.so.6 + 0x4EACF) [0x00007F192F495EA5] abort + 295 (libc.so.6 + 0x21EA5) [0x000055E24388D6C0] ? (splunkd + 0x1A366C0) [0x000055E24388D770] ? (splunkd + 0x1A36770) [0x000055E2445D6D24] _ZN29PipelineInputChannelReferenceC2EPPK3StrP23PipelineInputChannelSetb + 388 (splunkd + 0x277FD24) [0x000055E2445BACC3] _ZN12PipelineData11set_channelEPK3StrS2_S2_ + 243 (splunkd + 0x2763CC3) [0x000055E2445BAF9E] _ZN12PipelineData16recomputeConfKeyEP11PipelineSetb + 286 (splunkd + 0x2763F9E) [0x000055E243E3689E] _ZN24RegexExtractionProcessor4eachER15CowPipelineDataP18PipelineDataVectorb + 718 (splunkd + 0x1FDF89E) [0x000055E243E36BF3] _ZN24RegexExtractionProcessor12executeMultiER18PipelineDataVectorPS0_ + 67 (splunkd + 0x1FDFBF3) [0x000055E243BCD5F2] _ZN8Pipeline4mainEv + 1074 (splunkd + 0x1D765F2) [0x000055E244C336FD] _ZN6Thread37_callMainAndDiscardTerminateExceptionEv + 13 (splunkd + 0x2DDC6FD) [0x000055E244C345F2] _ZN6Thread8callMainEPv + 178 (splunkd + 0x2DDD5F2) [0x00007F192FF1F1CA] ? (libpthread.so.0 + 0x81CA) [0x00007F192F4ADE73] clone + 67 (libc.so.6 + 0x39E73) Last few lines of stderr (may contain info on assertion failure, but also could be old): Fatal thread error: pthread_mutex_lock: Invalid argument; 117 threads active, in typing_0                               Fatal thread error: pthread_mutex_lock: Invalid argument;                 This crash happens if persistent queue is enabled. It has been reported for several years. I see one reported back in 2015 as well. https://community.splunk.com/t5/Monitoring-Splunk/What-would-cause-a-Fatal-thread-error-in-thread-typing-found-in/m-p/261407 The bug existed always but the interesting part is, since 9.x the frequency of crashes has gone up. More customers are reporting the crashes now. The probability of hitting the race condition has gone up now. We are fixing the issue( internal ticket SPL-251434) for next patch, in the mean time here are few workarounds to consider depending on what is feasible for your requirement. The reason for 9.x high frequency of crashes on instance with persistent queue enabled is that the forwarders(UF/HF/IUF/IHF) are sending data at faster rate due to 9.x autoBatch, thus small in-memory part of persistent queue (default 500KB) makes it nearly impossible to not bring persistent queue part (writing on to disk) into play. Meaning now 9.x receiver with persistent queue is writing on to disk nearly all the time even when down stream pipeline queues are not saturated. So the best solution to bring crashing frequency to the level of 8.x or older is to increase  in-memory part of persistent queue ( so that if no down stream queues full not disk writes to persistent queue). However the fundamental bug still remains there and will be fixed in a patch.  The workarounds are reducing the possibility of disk writes for persistent queue. So have a look at the 3 possible workarounds and see which one works for you. 1. Turn off persistent queue on splunktcpin port( I sure not feasible for all). This will eliminate the crash. 2. Disable `splunk_internal_metrics`  app as it does source type cloning for metrics.log. Most of us probably not aware that metrics.log is cloned and additionally indexed into `_metrics` index. If you are not using `_metrics` index, disable the app. For crash to happen, you need two conditions    a) persistent queue   b) sourcetype cloning. 3. Apply following configs to reduce the chances of crashes. limits.conf  [input_channels] max_inactive=300001 lowater_inactive=300000 inactive_eligibility_age_seconds=120 inputs.conf, increase im-memory queue size of PQ( depending on ssl or non-ssl port) [splunktcp-ssl:<port>] queueSize=100MB [splunktcp:<port>] queueSize=100MB Enable Async Forwarding on HF/IUF/IHF (crashing instance)  4.  Slow down forwarders by setting `autoBatch=false` on all universal forwarders/heavy forwarders .  ... View more

CHECK_METHOD = modtime is not working as expected due to a regression in 9.x as there is wrong calculation which will lead to un-expected re-reading of a file. Until next patch, use following workaround for inputs with CHECK_METHOD = modtime In inputs.conf set following for impacted stanza time_before_close=0   ... View more