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Posted to commits@cassandra.apache.org by "Aditya Pandit (JIRA)" <ji...@apache.org> on 2016/09/02 20:49:21 UTC

[jira] [Commented] (CASSANDRA-12500) Counter cache hit counter not incrementing

    [ https://issues.apache.org/jira/browse/CASSANDRA-12500?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15459556#comment-15459556 ] 

Aditya Pandit commented on CASSANDRA-12500:
-------------------------------------------

CounterCache value gets hit on UPDATE operation of same row the CounterCache will register a hit as it re-uses the same Counter object.
example: add another update to the same row:

UPDATE test.test2 SET v=v+1 WHERE id=1 and c=2;

And then check nodetool info | grep Cache
I added one more row and updated it again to get 4 entries and saw 1 hit(for the one that I updated twice).

{noformat}
Key Cache              : entries 23, size 1.77 KiB, capacity 50 MiB, 70 hits, 92 requests, 0.761 recent hit rate, 14400 save period in seconds
Row Cache              : entries 0, size 0 bytes, capacity 10 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
Counter Cache          : entries 4, size 440 bytes, capacity 20 MiB, 1 hits, 2 requests, 0.500 recent hit rate, 7200 save period in seconds
Chunk Cache            : entries 26, size 1.62 MiB, capacity 219 MiB, 38 misses, 162 requests, 0.765 recent hit rate, 570.397 microseconds miss latency
{noformat}




> Counter cache hit counter not incrementing 
> -------------------------------------------
>
>                 Key: CASSANDRA-12500
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-12500
>             Project: Cassandra
>          Issue Type: Bug
>            Reporter: Jeff Jirsa
>            Priority: Minor
>
> Trivial repro on 3.7 with scripts below. Haven't dug through {{CounterCacheTest}} to find out if the cache is getting skipped or if it's just not updating the hit counter properly: 
> {code}
> #!/bin/sh
> ccm remove test
> ccm create test -v 3.7 -n 1
> sed -i'' -e 's/row_cache_size_in_mb: 0/row_cache_size_in_mb: 100/g' .ccm/test/node1/conf/cassandra.yaml
> ccm start
> sleep 5
> ccm node1 cqlsh < ~/keyspace.cql
> ccm node1 cqlsh < ~/table-counter.cql
> ccm node1 cqlsh < ~/table-counter-clustering.cql
> echo "Schema created, reads and writes starting"
> ccm node1 nodetool info | grep Cache
> echo "UPDATE test.test SET v=v+1 WHERE id=1; " | ccm node1 cqlsh
> echo "UPDATE test.test2 SET v=v+1 WHERE id=1 and c=1; " | ccm node1 cqlsh
> echo "UPDATE test.test2 SET v=v+1 WHERE id=1 and c=2; " | ccm node1 cqlsh
> echo "SELECT * FROM test.test WHERE id=1; " | ccm node1 cqlsh
> ccm node1 nodetool info | grep Cache
> echo "SELECT * FROM test.test WHERE id=1; " | ccm node1 cqlsh
> ccm node1 nodetool info | grep Cache
> echo "SELECT * FROM test.test2 WHERE id=1; " | ccm node1 cqlsh
> ccm node1 nodetool info | grep Cache
> echo "SELECT * FROM test.test2 WHERE id=1; " | ccm node1 cqlsh
> ccm node1 nodetool info | grep Cache
> echo "SELECT * FROM test.test2 WHERE id=1 and c=1; " | ccm node1 cqlsh
> ccm node1 nodetool info | grep Cache
> echo "SELECT * FROM test.test2 WHERE id=1 and c=1; " | ccm node1 cqlsh
> ccm node1 nodetool info | grep Cache
> {code}
> Keyspace / tables:
> {code}
> CREATE KEYSPACE test WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'}  AND durable_writes = true;
> {code}
> {code}
> CREATE TABLE test.test (
>     id int PRIMARY KEY,
>     v counter
> ) WITH caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'};
> {code}
> {code}
> CREATE TABLE test.test2 (
>     id int,
>     c int,
>     v counter,
>     PRIMARY KEY(id, c)
> ) WITH caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'};
> {code}
> Output:
> {code}
> Schema created, reads and writes starting
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 61 hits, 84 requests, 0.726 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 0, size 0 bytes, capacity 12 MiB, 0 hits, 0 requests, NaN recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 227 requests, 0.833 recent hit rate, 80.234 microseconds miss latency
>  id | v
> ----+---
>   1 | 1
> (1 rows)
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 70 hits, 93 requests, 0.753 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 3, size 328 bytes, capacity 12 MiB, 0 hits, 3 requests, 0.000 recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 288 requests, 0.868 recent hit rate, 80.234 microseconds miss latency
>  id | v
> ----+---
>   1 | 1
> (1 rows)
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 72 hits, 95 requests, 0.758 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 3, size 328 bytes, capacity 12 MiB, 0 hits, 3 requests, 0.000 recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 303 requests, 0.875 recent hit rate, 80.234 microseconds miss latency
>  id | c | v
> ----+---+---
>   1 | 1 | 1
>   1 | 2 | 1
> (2 rows)
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 74 hits, 97 requests, 0.763 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 3, size 328 bytes, capacity 12 MiB, 0 hits, 3 requests, 0.000 recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 318 requests, 0.881 recent hit rate, 80.234 microseconds miss latency
>  id | c | v
> ----+---+---
>   1 | 1 | 1
>   1 | 2 | 1
> (2 rows)
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 76 hits, 99 requests, 0.768 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 3, size 328 bytes, capacity 12 MiB, 0 hits, 3 requests, 0.000 recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 333 requests, 0.886 recent hit rate, 80.234 microseconds miss latency
>  id | c | v
> ----+---+---
>   1 | 1 | 1
> (1 rows)
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 78 hits, 101 requests, 0.772 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 3, size 328 bytes, capacity 12 MiB, 0 hits, 3 requests, 0.000 recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 348 requests, 0.891 recent hit rate, 80.234 microseconds miss latency
>  id | c | v
> ----+---+---
>   1 | 1 | 1
> (1 rows)
> Key Cache              : entries 17, size 1.29 KiB, capacity 24 MiB, 80 hits, 103 requests, 0.777 recent hit rate, 14400 save period in seconds
> Row Cache              : entries 0, size 0 bytes, capacity 100 MiB, 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds
> Counter Cache          : entries 3, size 328 bytes, capacity 12 MiB, 0 hits, 3 requests, 0.000 recent hit rate, 7200 save period in seconds
> Chunk Cache            : entries 14, size 896 KiB, capacity 91 MiB, 38 misses, 363 requests, 0.895 recent hit rate, 80.234 microseconds miss latency
> {code}



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