10.3. JMX Connector

The JMX connector provides the ability to query JMX information from all nodes in a Presto cluster. This is very useful for monitoring or debugging. Java Management Extensions (JMX) provides information about the Java Virtual Machine and all of the software running inside it. Presto itself is heavily instrumented via JMX.

Configuration

To configure the JMX connector, create a catalog properties file /etc/presto/catalog/jmx.properties with the following contents:

connector.name=jmx

Querying JMX

The JMX connector provides a single schema jmx that contains every Managed Bean (MBean) from every node in the Presto cluster. You can see all of the available MBeans by running SHOW TABLES:

SHOW TABLES FROM jmx.jmx;

MBean names map to non-standard table names and must be quoted with double quotes when referencing them in a query. For example, the following query shows the JVM version of every node:

SELECT node, vmname, vmversion
FROM jmx.jmx."java.lang:type=runtime";

                 node                 |              vmname               | vmversion
--------------------------------------+-----------------------------------+-----------
 ddc4df17-0b8e-4843-bb14-1b8af1a7451a | Java HotSpot(TM) 64-Bit Server VM | 24.60-b09
(1 row)

The following query shows the open and maximum file descriptor counts for each node:

SELECT openfiledescriptorcount, maxfiledescriptorcount
FROM jmx.jmx."java.lang:type=operatingsystem";

 openfiledescriptorcount | maxfiledescriptorcount
-------------------------+------------------------
                     329 |                  10240
(1 row)

Presto 0.127t Documentation