Table of Contents
JanusGraph supports Metrics. JanusGraph can measure the following:
- The number of transactions begun, committed, and rolled back
- The number of attempts and failures of each storage backend operation type
- The response time distribution of each storage backend operation type
To enable Metrics collection, set the following in JanusGraph’s properties file:
# Required to enable Metrics in JanusGraph
metrics.enabled = true
This setting makes JanusGraph record measurements at runtime using Metrics classes like Timer, Counter, Histogram, etc. To access these measurements, one or more Metrics reporters must be configured as described in the section Section 37.2, “Configuring Metrics Reporting”.
JanusGraph prefixes all metric names with "org.janusgraph" by default. This prefix can be set through the metrics.prefix
configuration property. For example, to shorten the default "org.janusgraph" prefix to just "janusgraph":
# Optional
metrics.prefix = janusgraph
Each JanusGraph transaction may optionally specify its own Metrics name prefix, overriding both the default Metrics name prefix and the metrics.prefix
configuration property. For example, the prefix could be changed to the name of the frontend application that opened the JanusGraph transaction. Note that Metrics maintains a ConcurrentHashMap of metric names and their associated objects in memory, so it’s probably a good idea to keep the number of distinct metric prefixes small.
To do this, call TransactionBuilder.setMetricsPrefix(String)
:
JanusGraph graph = ...;
TransactionBuilder tbuilder = graph.buildTransaction();
JanusGraphTransaction tx = tbuilder.groupName("foobar").start();
JanusGraph combines the Metrics for its various internal storage backend handles by default. All Metrics for storage backend interactions follow the pattern "<prefix>.stores.<opname>", regardless of whether they come from the ID store, edge store, etc. When metrics.merge-basic-metrics = false
is set in JanusGraph’s properties file, the "stores" string in metric names is replaced by "idStore", "edgeStore", "vertexIndexStore", or "edgeIndexStore".
JanusGraph supports the following Metrics reporters:
Each reporter type is independent of and can coexist with the others. For example, it’s possible to configure Ganglia, JMX, and Slf4j Metrics reporters to operate simultaneously. Just set all their respective configuration keys in janusgraph.properties (and enable metrics as directed above).
Table 37.1. Metrics Console Reporter Configuration Options
Config Key | Required? | Value | Default |
---|---|---|---|
metrics.console.interval | yes | Milliseconds to wait between dumping metrics to the console | null |
Example janusgraph.properties snippet that prints metrics to the console once a minute:
metrics.enabled = true # Required; specify logging interval in milliseconds metrics.console.interval = 60000
Table 37.2. Metrics CSV Reporter Configuration Options
Config Key | Required? | Value | Default |
---|---|---|---|
metrics.csv.interval | yes | Milliseconds to wait between writing CSV lines | null |
metrics.csv.directory | yes | Directory in which CSV files are written (will be created if it does not exist) | null |
Example janusgraph.properties snippet that writes CSV files once a minute to the directory ./foo/bar/
(relative to the process’s working directory):
metrics.enabled = true # Required; specify logging interval in milliseconds metrics.csv.interval = 60000 metrics.csv.directory = foo/bar
Note | |
---|---|
Configuration of Ganglia requires an additional library that is not packaged with JanusGraph due to its LGPL licensing that conflicts with the JanusGraph’s Apache 2.0 License. To run with Ganglia monitoring, download the |
Table 37.3. Metrics Ganglia Reporter Configuration Options
Config Key | Required? | Value | Default |
---|---|---|---|
metrics.ganglia.hostname | yes | Unicast host or multicast group to which our Metrics are sent | null |
metrics.ganglia.interval | yes | Milliseconds to wait between sending datagrams | null |
metrics.ganglia.port | no | UDP port to which we send Metrics datagrams | 8649 |
metrics.ganglia.addressing-mode | no | Must be "unicast" or "multicast" | unicast |
metrics.ganglia.ttl | no | Multicast datagram TTL; ignore for unicast | 1 |
metrics.ganglia.protocol-31 | no | Boolean; true to use Ganglia protocol 3.1, false to use 3.0 | true |
metrics.ganglia.uuid | no | null | |
metrics.ganglia.spoof | no | null |
Example janusgraph.properties snippet that sends unicast UDP datagrams to localhost on the default port once every 30 seconds:
metrics.enabled = true # Required; IP or hostname string metrics.ganglia.hostname = 127.0.0.1 # Required; specify logging interval in milliseconds metrics.ganglia.interval = 30000
Example janusgraph.properties snippet that sends unicast UDP datagrams to a non-default destination port and which also spoofs the IP and hostname reported to Ganglia:
metrics.enabled = true # Required; IP or hostname string metrics.ganglia.hostname = 1.2.3.4 # Required; specify logging interval in milliseconds metrics.ganglia.interval = 60000 # Optional metrics.ganglia.port = 6789 metrics.ganglia.spoof = 10.0.0.1:zombo.com
Table 37.4. Metrics Graphite Reporter Configuration Options
Config Key | Required? | Value | Default |
---|---|---|---|
metrics.graphite.hostname | yes | IP address or hostname to which Graphite plaintext protocol data are sent | null |
metrics.graphite.interval | yes | Milliseconds to wait between pushing data to Graphite | null |
metrics.graphite.port | no | Port to which Graphite plaintext protocol reports are sent | 2003 |
metrics.graphite.prefix | no | Arbitrary string prepended to all metric names sent to Graphite | null |
Example janusgraph.properties snippet that sends metrics to a Graphite server on 192.168.0.1 every minute:
metrics.enabled = true # Required; IP or hostname string metrics.graphite.hostname = 192.168.0.1 # Required; specify logging interval in milliseconds metrics.graphite.interval = 60000
Table 37.5. Metrics JMX Reporter Configuration Options
Config Key | Required? | Value | Default |
---|---|---|---|
metrics.jmx.enabled | yes | Boolean | false |
metrics.jmx.domain | no | Metrics will appear in this JMX domain | Metrics’s own default |
metrics.jmx.agentid | no | Metrics will be reported with this JMX agent ID | Metrics’s own default |
Example janusgraph.properties snippet:
metrics.enabled = true # Required metrics.jmx.enabled = true # Optional; if omitted, then Metrics uses its default values metrics.jmx.domain = foo metrics.jmx.agentid = baz
Table 37.6. Metrics Slf4j Reporter Configuration Options
Config Key | Required? | Value | Default |
---|---|---|---|
metrics.slf4j.interval | yes | Milliseconds to wait between dumping metrics to the logger | null |
metrics.slf4j.logger | no | Slf4j logger name to use | "metrics" |
Example janusgraph.properties snippet that logs metrics once a minute to the logger named foo
:
metrics.enabled = true # Required; specify logging interval in milliseconds metrics.slf4j.interval = 60000 # Optional; uses Metrics default when unset metrics.slf4j.logger = foo
In case the Metrics reporter configuration options listed above are insufficient, JanusGraph provides a utility method to access the single MetricRegistry
instance which holds all of its measurements.
com.codahale.metrics.MetricRegistry janusgraphRegistry = org.janusgraph.util.stats.MetricManager.INSTANCE.getRegistry();
Code that accesses janusgraphRegistry
this way can then attach non-standard reporter types or standard reporter types with exotic configurations to janusgraphRegistry
. This approach is also useful if the surrounding application already has a framework for Metrics reporter configuration, or if the application needs multiple differently-configured instances of one of JanusGraph’s supported reporter types. For instance, one could use this approach to setup multiple unicast Graphite reporters whereas JanusGraph’s properties configuration is limited to just one Graphite reporter.