Known issues

This topic lists known issues that are specific to the universal forwarder. For information on fixed issues, see Fixed issues.

Universal forwarder issues

Date filed	Issue number	Description
2021-09-15	SPL-212200, SPL-214114, SPL-214937	Heavy Forwarder crashed with Crashing thread TcpOutEloop : Splunk version 8.1.4 Workaround: Following configuration should reduce the frequency of crashes: limits.conf [input_channels] max_inactive = 50000 inactive_eligibility_age_seconds = 36000
2021-08-16	SPL-210384, SPL-211917	Rolling restart causes forwarders to block
2021-01-14	SPL-199409, SPL-204579, SPL-199691	Windows EventLog SIDs no longer resolving after upgrade to 8.1
2020-12-09	SPL-198468, SPL-196929	in outputs.conf, configure syslog forward to third party, when the third party syslog server hang, the whole HF stop sending data to indexer tier
2020-11-09	SPL-197140, SPL-234386	UF failed to start on Solaris 11.3 with error: "symbol in6addr_any: referenced symbol not found" Workaround: 1. Do not upgrade past Splunk 8.0.5 on Solaris 11.3 OR 2. Upgrade to Solaris 11.4
2020-09-29	SPL-195635, SPL-202178, SPL-206477, SPL-202163, SPL-206534	Splunkd increased memory usage over time when monitoring UDP port(s) with in inputs.conf
2019-05-28	SPL-171178, SPL-167307, SPL-202078	Indexer Acknowledgement causes metric index events that do not have "_raw" fields to be duplicated Workaround: Indexer acknowledgement is a feature that helps prevent loss of data when forwarders send data to an indexer. Indexer acknowledgement is controlled by the Boolean useACK setting in inputs.conf and outputs.conf. Indexer acknowledgement uses the _raw field to track completeness of delivery for each event. In some cases, when an event does not contain a valid _raw field, Splunk servers fail to determine whether the event is completely delivered and do not return acknowledgement for it, even when the event is processed successfully. As a result, the forwarder sends the same event again, leading to duplication of indexed data. This can affect metric indexes, where events with the JSON source type will not have _raw fields. When this issue occurs, the workaround is to set useACK=false to disable indexer acknowledgement. You may want to set up multiple forwarding/HEC channels or ports with two useACK settings, to meet the needs of both kinds of source events: those that contain the _raw field and those that do not.
2018-04-10	SPL-153251	Universal Forwarder txz package cannot be installed on FreeBSD 11.1 Workaround: 1. Use pkg install instead of pkg add OR 2. Install package by untarring tgz file to /opt/splunkforwarder
2017-03-20	SPL-139019	Possible compatibility issues between Python / SDK clients and new 6.6 and later default sslVersions, cipherSuites Workaround: Users can do either of the following: 1. Overwrite the new Splunk 6.6 server.conf [sslConfig] sslVersions, cipherSuites with your own settings that are compatible with your version of OpenSSL, e.g. the previous defaults from 6.5.x are compatible with OpenSSL 0.9.8 on Mac OSX: [sslConfig] sslVersions = *,-ssl2 sslVersionsForClient = *,-ssl2 cipherSuite = TLSv1+HIGH:TLSv1.2+HIGH:@STRENGTH 2. For some more up-to-date clients, it is possible to enforce TLS1.2 (e.g. --tlsv1.2 for curl) in order to connect successfully. 3. Upgrade OpenSSL on your platform and link it with your client (e.g. Python, curl, etc..). For example, OpenSSL 1.0.2 is currently available on Mac OSX via Homebrew (see https://brew.sh) and is compatible with the new Splunk 6.6 default sslVersions, cipherSuites.
2017-03-14	SPL-138731	New 6.6 and later default SHA256/2048-bit key certificates are not compatible with previous versions SHA1/1024-bit key certificates if cert verification is enabled Workaround: Users can do any of the following: 1. Disable certificate verification - the same root certificate is available with every Splunk download so enabling certificate verification while using the default certificates provides very little additional security. 2. Generate new SHA256/2048-bit key certificates using the new 6.6 root certificate and distribute to older versions of Splunk 3. Generate SHA1/1024-bit key certificates using the old root certificate to use with your new 6.6 instance. For convenience, the old root certificate is included in 6.6 in $SPLUNK_HOME/etc/auth/prev_release/
2015-06-10	SPL-103010	Indexing throughput on a forwarder with four pipelinesets drops 30% compared to a forwarder with two pipelinesets.
2015-04-14	SPL-99687, SPL-129637	Splunk universal forwarder is 7-10 days behind recent Windows Security and system log events. Workaround: To mitigate this, edit the following stanza in inputs.conf: [WinEventLog://Security] evt_resolve_ad_obj = 0.
2015-04-07	SPL-99316	Universal Forwarders stop sending data repeatedly throughout the day Workaround: In limits.conf, try changing file_tracking_db_threshold_mb in the [inputproc] stanza to a lower value.
2015-03-25	SPL-98594	Routing events to two different groups not working as expected. Workaround: 1 On the original UF, instead of configuring 1 s2s and 1 syslog group, configure 2 s2s groups. 2 Setup a proxy UF which takes input from the original UF and send input out syslog server. This solution only requires config change and no patch release is required.
2014-08-05	SPL-88396	After configuring a client name for a deployment client, the name is not shown in the Forwarder Management UI Workaround: Create a server class, where you can see the client name, and use that group when you add data.