Re: Cassandra FQL question-

[Akshith Mull]

And also we have Cassandra 4.0.5.

[cqlsh 6.0.0 | Cassandra 4.0.5 | CQL spec 3.4.5 | Native protocol v5]


Is this FQL & fqltool dump - will work on 4.0.x also right ?



> On Aug 9, 2023, at 9:18 AM, Akshith Mull  wrote:
> 
> 
> These are the class path settings , do we need to add anything here or is it 
> wrongly set?
> Any solution to fix this will be greatly appreciated,
> 
> cat /usr/bin/fqltool | grep CLASSPATH
> if [ -z "$CASSANDRA_CONF" -o -z "$CLASSPATH" ]; then
>echo "You must set the CASSANDRA_CONF and CLASSPATH vars" >&2
> "$JAVA" $JAVA_AGENT -ea -da:net.openhft... -cp "$CLASSPATH" $JVM_OPTS 
> -Xmx$MAX_HEAP_SIZE \
> 
> 
> 
> 
>> On Aug 8, 2023, at 12:57 PM, Miklosovic, Stefan 
>>  wrote:
>> 
>> Hey,
>> 
>> I did same steps from extracted tarball of 4.1.3 and it just works. It also 
>> works when I install Debian package.
>> 
>> The error you get seems like the class path is not set correctly so it can 
>> not load it.
>> 
>> You can probably debug this by wrapping last line in fqltool in "echo" to 
>> see what is on the class path.
>> 
>> Regards
>> 
>> 
>> From: Akshith Mull 
>> Sent: Tuesday, August 8, 2023 18:30
>> To: user@cassandra.apache.org
>> Subject: Cassandra FQL question-
>> 
>> You don't often get email from akshith.m...@gmail.com. Learn why this is 
>> important
>> NetApp Security WARNING: This is an external email. Do not click links or 
>> open attachments unless you recognize the sender and know the content is 
>> safe.
>> 
>> 
>> 
>> Hi All,
>> 
>> We have cassandra 4.x version,
>> 
>> I have enabled FQL as per the documentation-
>> 
>> 
>> Full Query Logging | Apache Cassandra 
>> Documentation
>> cassandra.apache.org
>> [favicon.ico]
>> 
>> 
>> nodetool enablefullquerylog --path /tmp/cassandrafullquerylog
>> 
>> 
>> 
>> Files generated.
>> 
>> 
>> -rw-r--r--   1131072 Aug  8 16:22 metadata.cq4t
>> 
>> -rw-r--r--   1 83886080 Aug  8 16:22 20230808-16.cq4
>> 
>> 
>> Its generated in binary .
>> 
>> 
>> As per the doc Im running dump command to convert human readable format.
>> 
>> 
>> fqltool dump /tmp/cassandrafullquerylog
>> 
>> 
>> But Im getting below error.
>> 
>> 
>> Error: Could not find or load main class 
>> org.apache.cassandra.fqltool.FullQueryLogTool
>> 
>> Caused by: java.lang.ClassNotFoundException: 
>> org.apache.cassandra.fqltool.FullQueryLogTool
>> 
>> 
>> Do we need to install anything to generate  the output ?
>> 
>> 
>> 
>> Gently appreciate the answers.
>> 
>> 
>> 
>> thanks
>> 
>> 
>> 
>> 
>> 
>> 
>> 
> 

Re: Cassandra p95 latencies

[Jeff Jirsa]

You’re going to have to help us help you 4.0 is pretty widely deployed. I’m not aware of a perf regression Can you give us a schema (anonymized) and queries and show us a trace ? On Aug 10, 2023, at 10:18 PM, Shaurya Gupta  wrote:The queries are rightly designed as I already explained. 40 ms is way too high as compared to what I seen with other DBs and many a times with Cassandra 3.x versions.CPU consumed as I mentioned is not high, it is around 20%.On Thu, Aug 10, 2023 at 5:14 PM MyWorld  wrote:Hi,P95 should not be a problem if rightly designed. Levelled compaction strategy further reduces this, however it consume some resources. For read, caching is also helpful. Can you check your cpu iowait as it could be the reason for delay Regards,AshishOn Fri, 11 Aug, 2023, 04:58 Shaurya Gupta,  wrote:Hi communityWhat is the expected P95 latency for Cassandra Read and Write queries executed with Local_Quorum over a table with 3 replicas ? The queries are done using the partition + clustering key and row size in bytes is not too much, maybe 1-2 KB maximum.Assuming CPU is not a crunch ?We observe those to be 40 ms P95 Reads and same for Writes. This looks very high as compared to what we expected. We are using Cassandra 4.0.Any documentation / numbers will be helpful.Thanks-- Shaurya Gupta

-- Shaurya Gupta

Re: Repair errors

[Surbhi Gupta]

Try sstablescrub on the node where it is showing corrupted data.

On Fri, Aug 11, 2023 at 8:38 AM Joe Obernberger <
joseph.obernber...@gmail.com> wrote:

> Finally found a message on another node that seem relevant:
>
> INFO  [CompactionExecutor:7413] 2023-08-11 11:36:22,397
> CompactionTask.java:164 - Compacting (d30b64ba-385c-11ee-8e74-edf5512ad115)
> [/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-97958-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-91664-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90239-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-99385-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-101078-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-86112-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90753-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-5-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-94008-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-92338-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-87273-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-82398-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-94244-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-80384-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-65431-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90412-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90104-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-85155-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-92914-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-78344-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-53269-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-99242-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-73898-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-100473-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-76035-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-101352-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-62093-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-93643-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-97812-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-73062-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-65491-big-Data.db:level=0,
> /data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-93299-big-Data.db:level=0,
> ]
> DEBUG [CompactionExecutor:7412] 2023-08-11 11:36:22,398
> Directories.java:502 - DataDirectory /data/7/cassandra/data has 9194752
> bytes available, checking if we can write 10716461 bytes
> INFO  [CompactionExecutor:7412] 2023-08-11 11:36:22,398
> CompactionTask.java:164 - Compacting (d30b64b0-385c-11ee-8e74-edf5512ad115)
> [/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-36867-big-Data.db:level=0,
> /data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-32270-big-Data.db:level=0,
> /data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-32287-big-Data.db:level=0,
> /data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-30785-big-Data.db:level=0,
> /data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-32545-big-Data.db:level=0,
> /data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-38791-big-Data.db:level=0,
> /data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-38586-big-Data.db:level=0,

Re: Repair errors

[Joe Obernberger]

Finally found a message on another node that seem relevant:

INFO  [CompactionExecutor:7413] 2023-08-11 11:36:22,397 
CompactionTask.java:164 - Compacting 
(d30b64ba-385c-11ee-8e74-edf5512ad115) 
[/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-97958-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-91664-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90239-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-99385-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-101078-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-86112-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90753-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-5-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-94008-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-92338-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-87273-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-82398-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-94244-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-80384-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-65431-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90412-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-90104-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-85155-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-92914-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-78344-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-53269-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-99242-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-73898-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-100473-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-76035-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-101352-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-62093-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-93643-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-97812-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-73062-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-65491-big-Data.db:level=0, 
/data/3/cassandra/data/doc/extractedmetadata-25c210e0ada011ebade9fdc1d34336d3/nb-93299-big-Data.db:level=0, 
]
DEBUG [CompactionExecutor:7412] 2023-08-11 11:36:22,398 
Directories.java:502 - DataDirectory /data/7/cassandra/data has 
9194752 bytes available, checking if we can write 10716461 bytes
INFO  [CompactionExecutor:7412] 2023-08-11 11:36:22,398 
CompactionTask.java:164 - Compacting 
(d30b64b0-385c-11ee-8e74-edf5512ad115) 
[/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-36867-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-32270-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-32287-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-30785-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-32545-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-38791-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-38586-big-Data.db:level=0, 
/data/3/cassandra/data/doc/source_correlations-4ce2d9f0912b11edbd6d4d9b3bfd78b2/nb-36849-big-Data.db:level=0, 

RE: Cassandra p95 latencies

[Durity, Sean R via user]

I would expect single digit ms latency on reads and writes. However, we have 
not done any performance testing on Apache Cassandra 4.x.

Sean R. Durity


INTERNAL USE
From: Shaurya Gupta 
Sent: Friday, August 11, 2023 1:16 AM
To: user@cassandra.apache.org
Subject: [EXTERNAL] Re: Cassandra p95 latencies

The queries are rightly designed as I already explained. 40 ms is way too high 
as compared to what I seen with other DBs and many a times with Cassandra 3. x 
versions. CPU consumed as I mentioned is not high, it is around 20%. On Thu, 
Aug 10,

The queries are rightly designed as I already explained. 40 ms is way too high 
as compared to what I seen with other DBs and many a times with Cassandra 3.x 
versions.
CPU consumed as I mentioned is not high, it is around 20%.

On Thu, Aug 10, 2023 at 5:14 PM MyWorld 
mailto:timeplus.1...@gmail.com>> wrote:
Hi,
P95 should not be a problem if rightly designed. Levelled compaction strategy 
further reduces this, however it consume some resources. For read, caching is 
also helpful.
Can you check your cpu iowait as it could be the reason for delay

Regards,
Ashish

On Fri, 11 Aug, 2023, 04:58 Shaurya Gupta, 
mailto:shaurya.n...@gmail.com>> wrote:
Hi community

What is the expected P95 latency for Cassandra Read and Write queries executed 
with Local_Quorum over a table with 3 replicas ? The queries are done using the 
partition + clustering key and row size in bytes is not too much, maybe 1-2 KB 
maximum.
Assuming CPU is not a crunch ?

We observe those to be 40 ms P95 Reads and same for Writes. This looks very 
high as compared to what we expected. We are using Cassandra 4.0.

Any documentation / numbers will be helpful.

Thanks
--
Shaurya Gupta



--
Shaurya Gupta




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