2009/6/25 Wheeler, JF (Jonathan) <jonathan.whee...@stfc.ac.uk>: >> -----Original Message----- >> From: Christopher McAtackney [mailto:crist...@gmail.com] >> Sent: 25 June 2009 14:51 >> >> Hi everyone, >> >> I have a quick question about Nagios and NDOUtils I was hoping someone >> could answer. >> >> What happens if the database that NDO Utils is using becomes >> unavailable? (e.g. the server has crashed). > > The answer depends a lot on whether you are using Nagios v2 or Nagios > v3; we are using Nagios v2.11. My understanding is that in Nagios v2, > the code that communicates with the event broker module in > single-threaded. Therefore a problem with the SQL server can jam up > Nagios to the extent that it effectively stops running commands. In > Nagios v3, threading has been rewritten and this problem no longer > exists.
Sorry, should have specified that. I'm running 3.0.6. >> I'm assuming Nagios will continue to monitor and send notifications as >> normal, is this correct? > > In Nagios v2 it seems that almost all activity is suspended when you are > using NDOutils and the MySQL server is unavailable; this continues until > the SQL server is restored. One solution is to restart Nagios without > the broker_module. > >> What about the service check results that would normally be passed to >> NDO Utils and then stored in the database? Are they queued somewhere? >> And if so, how is the capacity of this queue defined? If they are not >> queued, what happens? Will NDO Utils just throw an error for each >> result it tries to store in the database and fails? Will this affect >> the core Nagios process? > > Results passing into the command pipe are stored. The relevant > parameters are in nagios.cfg; they are external_command_buffer_slots and > check_result_buffer_slots - by default these are set to 4096 (see > documentation within the configuration file). Great, that's what I was hoping for. Do you have any experience of setting this buffer to much higher values? Not that I necessarily intend to, but it's always useful to know the effects of pushing the system to its limits. >> Hopefully someone can provide some insight. > > Hopefully this has Yes, this has been very helpful, thanks for your answer. Thanks as well Carsten, much appreciated. > Jonathan Wheeler > e-Science Centre > Rutherford Appleton Laboratory ------------------------------------------------------------------------------ _______________________________________________ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null