ZBX-17342-4.0.patch
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Causes |
Team A
[ZBX-17342] Value cache debug patch Created: 2020 Feb 19 Updated: 2024 Apr 10 Resolved: 2020 Mar 04 |
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| Status: | Closed |
| Project: | ZABBIX BUGS AND ISSUES |
| Component/s: | Server (S) |
| Affects Version/s: | None |
| Fix Version/s: | 4.0.19rc1, 4.4.7rc1, 5.0.0alpha3, 5.0 (plan) |
| Type: | Patch request | Priority: | Trivial |
| Reporter: | Valentins Grins | Assignee: | Vladislavs Sokurenko |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
ZBX-17342-4.0.patch
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| Issue Links: |
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| Team: | Team A |
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| Sprint: | Sprint 61 (Feb 2020) | ||||
| Story Points: | 0.25 | ||||
| Description |
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Under some circumstances it is possible that zabbix server logs are populated with messages that value cache is fully used, however internal metrics and charts for value cache does not show any deviations and it remains on the same level before and after. |
| Comments |
| Comment by dimir [ 2020 Feb 19 ] |
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Isn't this a feature request? |
| Comment by Ingus Vilnis [ 2020 Feb 19 ] |
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Well, if you consider a feature to not receive value cache is fully used: please increase ValueCacheSize configuration parameter message when internal graphs display you 60% free at 2GB allocated then... yes |
| Comment by dimir [ 2020 Feb 19 ] |
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Right. Sorry, I couldn't correctly make it out of the description. It looks too complicated. |
| Comment by Vladislavs Sokurenko [ 2020 Feb 19 ] |
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Could you please be so kind and provide affected version ? |
| Comment by Vladislavs Sokurenko [ 2020 Feb 19 ] |
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Example output:
191890:20200219:204405.908 === items with most values in value cache ===
191890:20200219:204405.909 itemid:28786 count:1152 perc:51.154529%
191890:20200219:204405.910 itemid:28742 count:40 perc:1.776199%
191890:20200219:204405.910 itemid:28743 count:40 perc:1.776199%
191890:20200219:204405.911 itemid:28752 count:40 perc:1.776199%
191890:20200219:204405.911 itemid:28762 count:40 perc:1.776199%
191890:20200219:204405.911 itemid:28741 count:39 perc:1.731794%
191890:20200219:204405.911 itemid:28751 count:39 perc:1.731794%
191890:20200219:204405.912 itemid:28748 count:38 perc:1.687389%
191890:20200219:204405.912 itemid:28738 count:38 perc:1.687389%
191890:20200219:204405.912 itemid:28763 count:38 perc:1.687389%
191890:20200219:204405.912 =============================================
191890:20200219:204405.913 === memory statistics for value cache size ===
191890:20200219:204405.914 free chunks of size 24 bytes: 1
191890:20200219:204405.916 min chunk size: 24 bytes
191890:20200219:204405.917 max chunk size: 24 bytes
191890:20200219:204405.917 memory of total size 130696 bytes fragmented into 1504 chunks
191890:20200219:204405.918 of those, 24 bytes are in 1 free chunks
191890:20200219:204405.919 of those, 106624 bytes are in 1503 used chunks
191890:20200219:204405.919 ================================
191890:20200219:204405.920 value cache is fully used: please increase ValueCacheSize configuration parameter
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| Comment by Vladislavs Sokurenko [ 2020 Feb 19 ] |
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Fixed in pull request feature/ZBX-17342-4.0 |
| Comment by Ingus Vilnis [ 2020 Feb 20 ] |
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Hi Vladislav, Output looks good. 4.0.11 would be the reported affected version. I know there is Anyways - Having extended debug of Value cache as well as History cache (I heard there is a patch too) in next minor releases of Zabbix would greatly help in troubleshooting of performance. |
| Comment by Vladislavs Sokurenko [ 2020 Feb 20 ] |
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Example: 57340:20200220:141431.995 === most used items statistics for value cache === 57340:20200220:141431.999 itemid:28733 active range:536 hits:1311 count:1313 perc:92.988669% 57340:20200220:141432.004 itemid:28791 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.004 itemid:28792 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.005 itemid:28784 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.005 itemid:28735 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.005 itemid:28788 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.005 itemid:28740 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.006 itemid:28757 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.006 itemid:28755 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.006 itemid:28783 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.006 itemid:28828 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.007 itemid:28745 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.007 itemid:28805 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.007 itemid:28782 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.008 itemid:28781 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.008 itemid:28823 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.008 itemid:28789 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.008 itemid:28793 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.009 itemid:28775 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.009 itemid:28812 active range:497 hits:0 count:1 perc:0.070822% 57340:20200220:141432.009 itemid:28822 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.009 itemid:28771 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.010 itemid:28810 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.010 itemid:28744 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.010 itemid:28766 active range:498 hits:0 count:1 perc:0.070822% 57340:20200220:141432.011 ============================================= 57340:20200220:141432.012 === memory statistics for value cache size === 57340:20200220:141432.013 min chunk size: 18446744073709551615 bytes 57340:20200220:141432.014 max chunk size: 0 bytes 57340:20200220:141432.014 memory of total size 130696 bytes fragmented into 1788 chunks 57340:20200220:141432.015 of those, 0 bytes are in 0 free chunks 57340:20200220:141432.016 of those, 102104 bytes are in 1788 used chunks 57340:20200220:141432.016 ================================================== 57340:20200220:141432.017 value cache is fully used: please increase ValueCacheSize configuration parameter |
| Comment by Vladislavs Sokurenko [ 2020 Feb 27 ] |
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Fixed in:
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"False positive" message is what this issue is about. It is thought to be memory fragmentation but there is no known way to troubleshoot it. So either the logged message is wrong or internal items are wrong.