Collecting system level diagnostics

Steps to collect system-wide performance information about a cluster using the DataStax Enterprise Performance Service.

The following system level diagnostic tables collect system-wide performance information about a cluster:
  • key_cache

    Per node key cache metrics. Equivalent to nodetool info.

  • net_stats

    Per node network information. Equivalent to nodetool netstats.

  • thread_pool

    Per node thread pool active/blocked/pending/completed statistics by pool. Equivalent to nodetool tpstats.

  • thread_pool_messages

    Per node counts of dropped messages by message type. Equivalent to nodetool tpstats.

Procedure

To collect system level data:

  1. Edit the dse.yaml file.

    dse.yaml

    The location of the dse.yaml file depends on the type of installation:

    Package installations
    Installer-Services installations

    		 /etc/dse/dse.yaml

    Tarball installations
    Installer-No Services installations

    		 installation_location/resources/dse/conf/dse.yaml
  2. In the dse.yaml file, set the enabled option for cql_system_info_options to true. 
    # CQL system info tables settings
cql_system_info_options:
    enabled: true
    refresh_rate_ms: 10000
  3. (Optional) To control how often the statistics are refreshed, increase or decrease the refresh_rate_ms parameter.

    The refresh_rate_ms specifies the length of the sampling period, that is, the frequency with which this data is updated.