Hello, I have a cluster of openldap servers behind a load balancer. Openldap writes its logs to syslog(). Rsyslog grabs them via imuxsock and writes them to files in /var/log and also ships them to a remote server. Nothing fancy...
The problem I have is that from time to time, the load balancer ejects a node from the cluster for a few seconds, which means openldap is blocked or is refusing new connections. This happens only when there's a diskfull on the node's /var/log, which is why I'm asking here. As a workaround, I recently changed my config to have 2 separate action queues, configured to drop logs when the queue is full ($ActionQueueDiscardSeverity 0 among other settings). Now using ps/top, I see the 2 "rs:action X" threads, which are sleeping most of the time. But what strikes me and worries me is that the "rs:main Q:Reg" thread is in D (uninterruptible sleep) state most of the time, waiting on "jbd2_log_wait_commit" (which is related to ext4 if I'm not mistaken). So I'm wondering: - why does the main-queue thread do any disk-related activity at all ? Shouldn't it just pass the logs down to the action-queues, and if any disk operations have to take place, they would happen in the action-queue threads ? - how can I be sure openldap will not block because rsyslog is having trouble ? It *seems* ok now with the capped action queues, but this thread in D state makes me wonder. NB: for the sake of understanding, I have disabled disk-assistance on all the queues at the moment. And iostat indeed shows almost no activity on the volume holding rsyslog's $WorkDirectory. This is running 5.8.10 (version shipped with RHEL6). I know it's old, and I'm open to upgrade it if needed. Thanks ! Marc _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com/professional-services/ What's up with rsyslog? Follow https://twitter.com/rgerhards NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T LIKE THAT.
