BestPractices

#Best Practices

Best Practices

JSON Organization

The JmxTransformer will attempt to internally optimize the way that you configure the hosts in your json files. If you can imagine, putting the same host in multiple files, with different queries could result in multiple server objects being generated. However, this is not the case if the Server objects are all the same, but just have different queries.

That said, in order to have the best experience, I suggest putting all of your queries into a single server block in the json.

Number of Threads

If you notice that it is taking a while to get through the list of Servers and all of the queries, it might make sense to spawn more threads to handle the requests. Obviously, this also means being on a multi-core processor so that the cpu can actually do work with those threads.

Security

JMX can be protected via login/password. This allow you to define different kind of users, some with read-write access, and others with just read access. JMXTrans doesn't need write access (in fact, JMXTrans code is read-only), so it is a good practice to use a dedicated read-only login for it.

In JSON, add username and password attributes to server, next to host and port :

{
  "servers" : [ {
    "port" : "1099",
    "host" : "w2",
    "username" : "collector",
    "password" : "1234567890",
    "queries" : [ {
      "obj" : "java.lang:type=Memory",
      "attr" : [ "HeapMemoryUsage", "NonHeapMemoryUsage" ],
      "outputWriters" : [ {
        "@class" : "com.googlecode.jmxtrans.model.output.RRDToolWriter",
        "settings" : {
            "templateFile" : "heapmemory-rrd-template.xml",
            "outputFile" : "target/heap.rrd",
            "binaryPath" : "/opt/local/bin",
            "debug" : true,
            "generate" : true
        }
      } ]
    } ]
  } ]
}

On JMX side, you could set it with com.sun.management.jmxremote.authenticate, com.sun.management.jmxremote.password.file, com.sun.management.jmxremote.access.file parameter values for example:

java -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.ssl=false \
-Dcom.sun.management.jmxremote.authenticate=true \
-Dcom.sun.management.jmxremote.password.file=/opt/myapp/etc/jmx.password \
-Dcom.sun.management.jmxremote.access.file=/opt/myapp/etc/jmx.access  \ com.mycorp.myproduct.MyApp start

jmx.access file will contains two roles/accounts, collector (read-only) and administrator (full-access) :

collector   readonly
administrator   readwrite

jmx.password file will contains login/password :

collector	1234567890
administrator	5c10b5b2cd673a0616d529aa5234b12ee7153808