Adding Java driver forum. Even we like to know more on this.
- Ajay On Wed, Apr 8, 2015 at 8:15 PM, Jack Krupansky <jack.krupan...@gmail.com> wrote: > Just a couple of quick comments: > > 1. The driver is supposed to be doing availability and load balancing > already. > 2. If your cluster is lightly loaded, it isn't necessary to be so precise > with load balancing. > 3. If your cluster is heavily loaded, it won't help. Solution is to expand > your cluster so that precise balancing of requests (beyond what the driver > does) is not required. > > Is there anything special about your use case that you feel is worth the > extra treatment? > > If you are having problems with the driver balancing requests and properly > detecting available nodes or see some room for improvement, make sure to > the issues so that they can be fixed. > > > -- Jack Krupansky > > On Wed, Apr 8, 2015 at 10:31 AM, Jiri Horky <ho...@avast.com> wrote: > >> Hi all, >> >> we are thinking of how to best proceed with availability testing of >> Cassandra nodes. It is becoming more and more apparent that it is rather >> complex task. We thought that we should try to read and write to each >> cassandra node to "monitoring" keyspace with a unique value with low >> TTL. This helps to find an issue but it also triggers flapping of >> unaffected hosts, as the key of the value which is beining inserted >> sometimes belongs to an affected host and sometimes not. Now, we could >> calculate the right value to insert so we can be sure it will hit the >> host we are connecting to, but then, you have replication factor and >> consistency level, so you can not be really sure that it actually tests >> ability of the given host to write values. >> >> So we ended up thinking that the best approach is to connect to each >> individual host, read some system keyspace (which might be on a >> different disk drive...), which should be local, and then check several >> JMX values that could indicate an error + JVM statitics (full heap, gc >> overhead). Moreover, we will more monitor our applications that are >> using cassandra (with mostly datastax driver) and try to get fail node >> information from them. >> >> How others do the testing? >> >> Jirka H. >> > >
