Collecting database summary diagnostics
Steps to enable collecting database summary diagnostics using the DataStax Enterprise Performance Service.
You can enable collecting database summary diagnostics using the DataStax Enterprise Performance Service.
- node_table_snapshot
Per node lifetime table metrics broken down by keyspace and table.
- table_snapshot
Cluster wide lifetime table metrics broken down by keyspace and table (aggregates node_table_snapshot from each node in the cluster).
- keyspace_snapshot
Cluster wide lifetime table metrics, aggregated at the keyspace level (rolls up the data in table_snapshot).
dse.yaml
The location of the dse.yaml file depends on the type of installation:
Package installations |
/etc/dse/dse.yaml |
Tarball installations |
installation_location/resources/dse/conf/dse.yaml |
Examples
These example commands make temporarily changes only. Changes made with performance object subcommands do not persist between restarts and are useful only for short-term diagnostics.
See Collecting database summary diagnostics.
To enable the collection of database-level statistics data:
dsetool perf clustersummary enable
To disable the collection of database-level statistics data:
dsetool perf clustersummary disable
To keep slow queries in-memory only:
dsetool perf cqlslowlog skip_writing_to_db
To set the number of slow queries to keep in-memory:
dsetool perf cqlslowlog set_num_slowest_queries 5
To write slow queries to the database:
dsetool perf cqlslowlog write_to_db
To disable collecting information on slow queries:
dsetool perf cqlslowlog disable
To change the threshold to collect information on 5% of the slowest queries:
dsetool perf cqlslowlog 95.0
To enable collecting information to identify slow search queries:
dsetool perf solrslowlog enable
To change the threshold value (in milliseconds) at which a sub-query is slow enough to be reported:
dsetool perf solrslowlog 200
Procedure
-
Edit the dse.yaml file.
-
In the dse.yaml file, set the enabled option for
db_summary_stats_options
to true.# Database summary stats options db_summary_stats_options: enabled: true refresh_rate_ms: 10000
-
(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.
Example
dsetool perf clustersummary enableTo temporarily disable the collection of database-level statistics data:
dsetool perf clustersummary disable