JMX Metrics [Cassandra-Stress-Tool VS JMX]
Hi everyone! Which function has to be used with each JMX Metric Type? https://cassandra.apache.org/doc/latest/operating/metrics.html https://www.datadoghq.com/blog/how-to-collect-cassandra-metrics/ For example: to compute the read latency I did a ratio between ReadTotalLatency_Count JMX Counter and ReadLatency_Count JMX Timer, and the number corresponds to the one exposed via nodetool tablestats . How should I consider the attributes: 95thPercentile, Mean etc... from ReadLatency bean org.apache.cassandra.metrics:type=Table,keyspace=test,scope=test_column_family,name=ReadLatency I found also a grafana open-source dashboard https://grafana.com/grafana/dashboards/5408 but I am not convinced about the displayed numbers if I compare with the numbers shown by the cassandra-stress tool. If I want the QPS does it make sense to use rate(WriteLatencyCount[5m]) in grafana ? The latency computed by the cassandra-stress-tool should almost match the latency shown by the JMX metrics or not? Which one do you monitor ClientRequest metrics or Table metrics or ColumnFamily? I am going to create my Grafana dashboard and explain how I configured it. Best, Sergio - To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
Re: Find large partition https://github.com/tolbertam/sstable-tools
Thanks! I will look into it On 2019/11/22 19:22:15, Jeff Jirsa wrote: > Brian Gallew has a very simple script that does something similar: > https://github.com/BrianGallew/cassandra_tools/blob/master/poison_pill_tester > > You can also search the logs for messages about writing large partitions > during compaction. > > > > > > On Thu, Nov 21, 2019 at 6:33 PM Sergio Bilello > wrote: > > > Hi guys! > > Just for curiosity do you know anything beside > > https://github.com/tolbertam/sstable-tools to find a large partition? > > Best, > > > > Sergio > > > > - > > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > > For additional commands, e-mail: user-h...@cassandra.apache.org > > > > > - To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
Re: Find large partition https://github.com/tolbertam/sstable-tools
Brian Gallew has a very simple script that does something similar: https://github.com/BrianGallew/cassandra_tools/blob/master/poison_pill_tester You can also search the logs for messages about writing large partitions during compaction. On Thu, Nov 21, 2019 at 6:33 PM Sergio Bilello wrote: > Hi guys! > Just for curiosity do you know anything beside > https://github.com/tolbertam/sstable-tools to find a large partition? > Best, > > Sergio > > - > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > >
Re: Find large partition https://github.com/tolbertam/sstable-tools
It's apache licensed: https://github.com/instaclustr/cassandra-sstable-tools/blob/cassandra-3.11/LICENSE On Fri, Nov 22, 2019 at 12:06 AM Ahmed Eljami wrote: > I found this project on instaclustr github but I dont have any idea about > license: > > > https://github.com/instaclustr/cassandra-sstable-tools/blob/cassandra-3.11/README.md > > > > Le ven. 22 nov. 2019 à 03:33, Sergio Bilello > a écrit : > >> Hi guys! >> Just for curiosity do you know anything beside >> https://github.com/tolbertam/sstable-tools to find a large partition? >> Best, >> >> Sergio >> >> - >> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org >> For additional commands, e-mail: user-h...@cassandra.apache.org >> >>
Re: re-add column with same UDT fail
Hi,
Thanks for your replay.
I was starting to suspect something like this, by your description there
dosen't seam to be a straight forward fix for the issue, if it can be fixed at
all in a good way.
For me this was a really minor issue, it was just in a test case that I could
rewrite so I didn't have to recreate the column.
Thanks,
Tommy
On tor, 2019-11-21 at 23:01 -0800, Andrew Prudhomme wrote:
It looks like there are a couple of things going on here. The type check when
adding a UDT column:
new_type.isValueCompatibleWith(dropped_type)
will only be true if the dropped type is a UDT. This however will never be the
case, since UDT types are replaced with tuple when converted to a dropped
column type.
Though re-adding the UDT should be safe, it will not always be safe. Since
there is currently no way to record a non-frozen tuple, a frozen and non-frozen
UDT will both produce the same dropped column type (leading to
CASSANDRA-14673). So it is technically safer to reject the add (though the
table would already be corrupted and this would keep you from fixing it).
However, there are some inconsistencies. Had this check used the (presumably
stricter) isCompatibleWith check, it would have passed since it treats both as
tuple type. Also, you are able to re-add the column as a tuple, which would be
incompatible with non-frozen UDT data.
On Thu, Nov 21, 2019 at 5:59 AM Tommy Stendahl
wrote:
Hi,
I run in to problem with 3.11.5, I think its related to "* Toughen up column
drop/recreate type validations (CASSANDRA-15204)"
I have a user defined type and I have a table with a column that has this UDF
as type, if I drop the column and recreate it with the same name it fails. I
think this should work, it did in 3.11.4, or I'm I missing something?
I recreated this in cqlsh:
cqlsh> CREATE KEYSPACE foo WITH replication = {'class': 'SimpleStrategy',
'replication_factor': '1'};
cqlsh> CREATE TYPE foo.my_type (a int, b int );
cqlsh> CREATE TABLE foo.bar ( x int PRIMARY KEY, y int, z frozen );
cqlsh> ALTER TABLE foo.bar DROP z ;
cqlsh> ALTER TABLE foo.bar ADD z frozen;
InvalidRequest: Error from server: code=2200 [Invalid query] message="Cannot
re-add previously dropped column 'z' of type frozen, incompatible with
previous type frozen>"
cqlsh>
Regards,
Tommy
Re: Find large partition https://github.com/tolbertam/sstable-tools
I found this project on instaclustr github but I dont have any idea about license: https://github.com/instaclustr/cassandra-sstable-tools/blob/cassandra-3.11/README.md Le ven. 22 nov. 2019 à 03:33, Sergio Bilello a écrit : > Hi guys! > Just for curiosity do you know anything beside > https://github.com/tolbertam/sstable-tools to find a large partition? > Best, > > Sergio > > - > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > >
