Forum Discussion
NimbostratusReporting of hitting Connection Limits
We're using pool-member connection limits to prevent servers being overloaded. We can see from the statistics that these limits are being hit. The same statistics suggest that we're hitting the sum of all of the member limits, which would imply that we're turning some connections away.
I used these limits in a previous job running on LTM 9.x, and I remember getting log messages when the overall limit had been hit and turnaways have occurred. However, we're not seeing any such messages on 11.2. We currently have the "Layer 4" category as Informational.
I thought there was an SNMP trap in this case, as well. However, I don't see any relevant entries in /etc/alertd/alert.conf, nor do I see any MIB entries that seem relevant.
Is there any built-in way of getting an alert when we reject a user? Is it necessary to use an iRule to get this information?
4 Replies
What_Lies_Bene1Cirrostratus
Not sure about the logging or SNMP but it's possible you are benefiting from the Connection/Request Queuing feature in v11.
http://support.f5.com/content/kb/en-us/products/big-ip_ltm/manuals/product/ltm_implementations_11_0_0/_jcr_content/pdfAttach/download/file.res/ltm_impl_v11_0.pdf
Craig_Jackson_2After posting my original question, I read about the queuing facility and the LB_QUEUED event. It looks like one indeed can use LB_QUEUED to output a message.
However, the relevant pools have queuing turned off. What happens in that case?- What_Lies_Bene1I didn't actually know you could turn it off, I'll have to look into that. Anyway, I think logging a message for each connection exceeded could pose a risk to the system and that's probably why you don't get a message. However, apparently when the connection limit is reached for a pool member or node, the device's status changes to Unavailable and I assume this event is logged? If not I'm sure it could be configured to be logged.
- Craig_Jackson_2In any case, I think something was logged in 9.x.
