> Of course I have yet another question. Even if I assume the state of each > node is correct, how do I know if the cluster overall is considered healthy? > This may not be a valid question, but I hope it is. For example, if the > cluster configuration requires 3 nodes to write, I can write some fairly > detailed code in riak-java-client to realize that's the configuration and > count that there are enough healthy nodes. However, if I'm using something > like haproxy, I'm not sure there's a great spot to put that logic. > > Is there a way to query the cluster overall to ask a health question like > this?
Hi David, Alex's suggestion to use the PR and PW parameters for reads and writes could be used to create a health check within your application. However, I recommend not worrying too much about this issue within your application, as Riak is designed to be fault-tolerant. Instead focus on having a robust monitoring system in place for both Riak and your servers: http://docs.basho.com/riak/latest/ops/running/stats-and-monitoring/ Monitoring the performance of your cluster and alerting on increased latency or other outlier situations is a better approach, in my opinion. -- Luke Bakken Engineer [email protected] > On 12/8/15 1:09 PM, Alexander Sicular wrote: >> >> Besides just plainly writing a key, you could also do something like >> (pseudo code): >> >> Riak.put(canaryKey, pw=n_val){ >> If ok -> cool! >> If borked -> sad face >> } >> >> The important bit is the pw (primary write) equals your replication value. >> This means that all copies in the virtual node replica set need to go to >> virtual nodes allocated to their primary physical machines. This is a way >> you can check cluster status from the app level as in , is the cluster in >> some kind of borked state. >> >> -Alexander _______________________________________________ riak-users mailing list [email protected] http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
