README
¶
Cassandra collector
Cassandra is an open-source NoSQL database management system.
This module will monitor one or more Cassandra servers, depending on your configuration.
Requirements
- Cassandra with Prometheus JMX Exporter.
To configure Cassandra with the JMX Exporter:
Note: paths can differ depends on your setup.
- Download latest jmx_exporter jar file and install it in a directory where Cassandra can access it.
- Add
the jmx_exporter.yaml
file to
/etc/cassandra. - Add the following line to
/etc/cassandra/cassandra-env.shJVM_OPTS="$JVM_OPTS $JVM_EXTRA_OPTS -javaagent:/opt/jmx_exporter/jmx_exporter.jar=7072:/etc/cassandra/jmx_exporter.yaml - Restart cassandra service.
Metrics
All metrics have "cassandra." prefix.
Labels per scope:
- global: no labels.
- thread pool: thread_pool.
| Metric | Scope | Dimensions | Units |
|---|---|---|---|
| client_requests_rate | global | read, write | requests/s |
| client_request_read_latency_histogram | global | read, write | seconds |
| client_request_write_latency_histogram | global | read, write | seconds |
| client_requests_latency | global | read, write | seconds |
| row_cache_hit_ratio | global | hit_ratio | percentage |
| row_cache_hit_rate | global | hits, misses | events/s |
| row_cache_utilization | global | used | percentage |
| row_cache_size | global | size | bytes |
| key_cache_hit_ratio | global | hit_ratio | percentage |
| key_cache_hit_rate | global | hits, misses | events/s |
| key_cache_utilization | global | used | percentage |
| key_cache_size | global | size | bytes |
| storage_live_disk_space_used | global | used | bytes |
| compaction_completed_tasks_rate | global | completed | tasks/s |
| compaction_pending_tasks_count | global | pending | tasks |
| compaction_compacted_rate | global | compacted | bytes/s |
| thread_pool_active_tasks_count | thread pool | active | tasks |
| thread_pool_pending_tasks_count | thread pool | pending | tasks |
| thread_pool_blocked_tasks_count | thread pool | blocked | tasks |
| thread_pool_blocked_tasks_rate | thread pool | blocked | tasks/s |
| jvm_memory_used | global | heap, nonheap | bytes |
| jvm_gc_rate | global | parnew, cms | gc/s |
| jvm_gc_time | global | parnew, cms | seconds |
| dropped_messages_rate | global | dropped | messages/s |
| client_requests_timeouts_rate | global | read, write | timeout/s |
| client_requests_unavailables_rate | global | read, write | exceptions/s |
| client_requests_failures_rate | global | read, write | failures/s |
| storage_exceptions_rate | global | storage | exceptions/s |
Configuration
Edit the go.d/cassandra.conf configuration file using edit-config from the
Netdata config directory, which is typically at /etc/netdata.
cd /etc/netdata # Replace this path with your Netdata config directory
sudo ./edit-config go.d/cassandra.conf
Here is an example for 2 servers:
jobs:
- name: local
url: http://127.0.0.1:7072/metrics
- name: remote
url: http://203.0.113.10:7072/metrics
For all available options please see module configuration file.
Troubleshooting
To troubleshoot issues with the cassandra collector, run the go.d.plugin with the debug option enabled. The output
should give you clues as to why the collector isn't working.
-
Navigate to the
plugins.ddirectory, usually at/usr/libexec/netdata/plugins.d/. If that's not the case on your system, opennetdata.confand look for thepluginssetting under[directories].cd /usr/libexec/netdata/plugins.d/ -
Switch to the
netdatauser.sudo -u netdata -s -
Run the
go.d.pluginto debug the collector:./go.d.plugin -d -m cassandra
Documentation
Source Files