More than 100 items having missing data for more than 10 minutes

[ukarm105]

Hello all,

We use to receive this warning several times a day and I would like to find out what is happening. Actually the only thing I was able to find is a graph displaying how many items are not available in a time. But is it possible to check what these items are? Or is there any known issue causing this warning?

Many thanks for any help!
Martin

[LenR]

Go to Administrative, Queue. There are 3 different displays to show missing items.

If a server goes offline and it has 100 items, there is 100 missing items, so it's often just a case of a server going away, but these screens will show your environment.

[ukarm105]

Hi LenR,

Thanks. So if I go to Details, there is a Queue of items to be updated. What i do not understand are items like Client Associated To Ap which are aging out (and there is a lot of them).. This is from the wireless controller. Any idea how to fix this?

Again, thank you for your help.

[LenR]

Is that an LLD item? I'm not familiar with that item, could it be like a discovered wifi client that has left the AP? If so, it's a hopeless missing item until the device returns (if ever) or the LLD age to delete is reached.

There is nothing that says 100 missing items is a problem in your environment, it's just a default trigger setting. I've raised my values to something larger and added a trigger for growth instead of just a number.

[ukarm105]

I have found out that this seems to be a problem with something else, not with this trigger. Actually, there seems to be a problem with the performance, but I have no idea why. From time to time, is seems the proxy is not able to handle all the messages and in that time there is a lot of false warnings that the items have missing data for more than 10 minutes. I understood it like the proxy receives the data, but is not processing it. Here is the performance graph.When the queue (the red one) is big, we run into issues. Any idea why is this happening? CPU and memory are almost unused.. Thanks for your time!

[LenR]

What version of Zabbix? Check the server performance graphs during the same times. Is housekeeping active?

[ukarm105]

We use Zabbix 3.4.4. I also checked all graphs and cannot see any relation between the performance graph and any other.. What is housekeeping?

[ukarm105]

Hi, we are still getting these errors, does anyone have an idea? Thanks..

[tim.mooney]

Housekeeping is a Zabbix subsystem that is responsible for cleaning out old or outdated values. See: https://www.zabbix.com/documentation...oncepts/server

Dealing with the 'history' and 'trends' data is something that sites have periodically had issues with. Various schemes (like database partitioning) exist to reduce the I/O load that old value cleanup places on your system.

On a standard install, if housekeeping isn't running frequently enough, then when it does run it has a *lot* of work to do, so it can cause I/O issues for other processes. You don't want to run it *too* frequently though.

Note: housekeeping happens on your main Zabbix server.

[ukarm105]

Thank you for your response. So I check the graphs and can see this - graph for last 6 hrs, the issue is present - is can bee seen in a performance graph as the queue is high. As you can see the housekeeper is scheduled for each hour to process old data. The issue we have - the problem More than 100 items having missing data for more than 10 minutes.. is like for last 3 hrs now. Can you see something suspicious?