Collecting object I/O level diagnostics

Steps to collect data on object I/O statistics using the DataStax Enterprise Performance Service.

The following object I/O level diagnostic tables collect data on object I/O statistics:
  • object_io

    Per node recent latency metrics by keyspace and table.

  • object_read_io_snapshot

    Per node recent latency metrics, broken down by keyspace and table and orders data by mean read latency.

  • object_write_io_snapshot

    Per node recent latency metrics, broken down by keyspace and table and orders data mean write latency.

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

Procedure

To enable the collection of this data:

  1. Edit the dse.yaml file.
  2. In the dse.yaml file, set the enabled option for resource_level_latency_tracking_options to true. 
    # Data Resource latency tracking settings
resource_level_latency_tracking_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.