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https://issues.apache.org/jira/browse/CASSANDRA-17062?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17443143#comment-17443143
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Aleksei Zotov commented on CASSANDRA-17062:
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[~samt] [~blerer]
I've started working on this and mentioned a discrepancy between non-auth (key,
row, counter, chunk) and auth caches. The non-auth caches are weighted (they do
care about weight of a single entry) whereas the auth caches are non-weighted.
Particularly it affects _Capacity_ and _Size_ attributes of the MBeans. For
weighted caches they represent size of entries in bytes, for non-weighted
caches they represent number of entries.
Current changes do not particularly handle this logical discrepancy (the only
thing I've done is renaming of capacity_bytes -> capacity and size_bytes ->
size in the corresponding VT). What can be actually done to make the logic a
bit clearer:
# Introduce "weighted" column to the VT and add corresponding notes to the
documentation on how to treat capacity and size for weighted/non-weighted
caches. But we can mention that without having the new column.
# Make auth caches weighted. I feel it would make things even worse because it
is not really required from logical standpoint (and it would be hard to
precisely calculate used memory for auth caches).
# Completely separate metrics for weighted and non-weighted caches. It is
opposite to unification I supposed to achieve by this ticket. However, it
should make things clear and precise.
Please, share your thoughts (maybe you have other ideas). I linked a draft PR
for your reference.
> Expose Auth Caches metrics
> --------------------------
>
> Key: CASSANDRA-17062
> URL: https://issues.apache.org/jira/browse/CASSANDRA-17062
> Project: Cassandra
> Issue Type: Improvement
> Components: Feature/Virtual Tables, Observability/Metrics,
> Tool/nodetool
> Reporter: Aleksei Zotov
> Assignee: Aleksei Zotov
> Priority: Normal
> Fix For: 4.x
>
>
> Unlike to other caches (row, key, counter), Auth Caches lack some monitoring
> capabilities. Here are a few particular changes to get this inequity fixed:
> # Add auth caches to _system_views.caches_ VT
> # Expose auth caches metrics via JMX
> # Add auth caches details to _nodetool info_
>
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