Re: Cassandra JMX without RMI?
Hello, I haven't found any good documentation to refer to, but you can have a look at the following: https://github.com/apache/cassandra-sidecar https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=95652224 The sidecar is deployed alongside the Cassandra node and exposes metrics/commands via HTTP/REST. This is what it look like: https://cwiki.apache.org/confluence/download/attachments/247827919/SBW%20OSS%20SBR.jpg?version=1=1681166031000=v2 On Wed, 19 Jul 2023 at 19:00, Angelo Polo wrote: > > Thanks Max, that's a good option to know about. > > Unfortunately I have a fairly strict requirement for an agentless > architecture. It's possible to have some values set in cassandra-env for > example, but I can't say "download and install this jar here" (Jalokia agent > mode) or "run this code from here" (Jalokia proxy mode - Jalokia would still > be using JMX over RMI I assume, but the proxy shields my application from > having to make RMI calls directly). > > Is JMX over RMI the only out-of-the-box way to communicate remotely with > Cassandra's MBean server? > > Best, > Angelo > > On Tue, Jul 18, 2023 at 11:49 PM Max Campos wrote: >> >> We use Jolokia. It runs inside of Cassandra and then gives you an HTTP REST >> interface to interact with JMX. Works great for us! >> >> https://jolokia.org/ >> >> - Max >> >> On Jul 18, 2023, at 8:11 pm, Angelo Polo wrote: >> >> Is it possible to connect to the Cassandra JMX server without using the RMI >> protocol? >> >> I have found for example, this open source project >> https://github.com/willemsrb/simple-jmx that claims to provide JMX without >> RMI, but it seems to need to be set up on the server side too, and of course >> Cassandra's JMX server isn't based on this project. >> >> So is there a client-side-only possibility to use something other than RMI >> when retrieving Cassandra JMX? >> >> Thanks, >> Angelo >> >>
Re: Cassandra JMX without RMI?
Thanks Max, that's a good option to know about. Unfortunately I have a fairly strict requirement for an agentless architecture. It's possible to have some values set in cassandra-env for example, but I can't say "download and install this jar here" (Jalokia agent mode) or "run this code from here" (Jalokia proxy mode - Jalokia would still be using JMX over RMI I assume, but the proxy shields my application from having to make RMI calls directly). Is JMX over RMI the only out-of-the-box way to communicate remotely with Cassandra's MBean server? Best, Angelo On Tue, Jul 18, 2023 at 11:49 PM Max Campos wrote: > We use Jolokia. It runs inside of Cassandra and then gives you an HTTP > REST interface to interact with JMX. Works great for us! > > https://jolokia.org/ > > - Max > > On Jul 18, 2023, at 8:11 pm, Angelo Polo wrote: > > Is it possible to connect to the Cassandra JMX server without using the > RMI protocol? > > I have found for example, this open source project > https://github.com/willemsrb/simple-jmx that claims to provide JMX > without RMI, but it seems to need to be set up on the server side too, and > of course Cassandra's JMX server isn't based on this project. > > So is there a client-side-only possibility to use something other than RMI > when retrieving Cassandra JMX? > > Thanks, > Angelo > > >
LocalQuorum requiring 3 replicas with RF=3 when a node is joining
Hello. This company I am working for has small production cluster with the following setup: 2 DCs 3 nodes each RF = 3 (all keyspaces) num_tokens = 4 repairs are up to date We are in the process of adding more nodes to the cluster, although while testing our procedures on a staging cluster (same setup), we constantly get this error while the new node is in JOINING or LEAVING stage: "Server timeout during read query at consistency LocalQuorum (2 replica(s) responded over 3 required)" Trying to understand why would Cassandra require 3 replicas when the node is joining the cluster, when the quorum should be 2. We have no such error when one of the three nodes is down as expected. I have been bouncing around this error for a while now, so any hints or thoughts would be much appreciated. Thank you Luciano
