dsetool perf

Temporarily changes the running parameters for the CQL Performance Service. Histogram tables provide DSE statistics that can be queried with CQL.

Changes made with performance object subcommands do not persist between restarts and are useful only for short-term diagnostics.

To make these changes permanent, change the CQL Performance Service options in dse.yaml.

Synopsis

dsetool perf <subcommand> <values>
Syntax conventions Description

UPPERCASE

Literal keyword.

Lowercase

Not literal.

<`Italics>`

Variable value. Replace with a valid option or user-defined value.

[ ]

Optional. Square brackets ( [ ] ) surround optional command arguments. Do not type the square brackets.

( )

Group. Parentheses ( ( ) ) identify a group to choose from. Do not type the parentheses.

|

Or. A vertical bar ( | ) separates alternative elements. Type any one of the elements. Do not type the vertical bar.

...

Repeatable. An ellipsis ( ... ) indicates that you can repeat the syntax element as often as required.

'<Literal string>'

Single quotation ( ' ) marks must surround literal strings in CQL statements. Use single quotation marks to preserve upper case.

{ <key>:<value> }

Map collection. Braces ( { } ) enclose map collections or key value pairs. A colon separates the key and the value.

<<datatype1>,<datatype2>>

Set, list, map, or tuple. Angle brackets ( < > ) enclose data types in a set, list, map, or tuple. Separate the data types with a comma.

cql_statement;

End CQL statement. A semicolon ( ; ) terminates all CQL statements.

[ -- ]

Separate the command line options from the command arguments with two hyphens ( -- ). This syntax is useful when arguments might be mistaken for command line options.

' <<schema> ... </schema> >'

Search CQL only: Single quotation marks ( ' ) surround an entire XML schema declaration.

@<xml_entity>='<xml_entity_type>'

Search CQL only: Identify the entity and literal value to overwrite the XML element in the schema and solrconfig files.

clustersummary enable | disable

Whether to enable the collection of database-level statistics for the cluster.

cqlslowlog enable | disable

Whether to enable the collection of CQL queries that exceed the specified time threshold.

cqlslowlog [threshold]

This command sets the CQL slow log threshold, allowing for the specification of an exact threshold as a discrete value in milliseconds or as a percentile of the actual request times.

Configuration options include:

  • Values in the range [0,1] are interpreted as a percentile threshold.

  • Values greater than 1 are treated as an absolute, discrete threshold in milliseconds.

  • A value of 1.0 implies no queries are logged.

  • Percentile values are expressed in decimal form:

    • 0.999 logs 0.1% of the slowest queries.

    • 0.95 logs 5% of the slowest queries.

    • 0.5 logs 50% of the slowest queries.

  • A value of 0.0 logs all queries.

cqlslowlog skip_writing_to_db

Keeps slow queries in-memory only.

cqlslowlog write_to_db

Writes data to the database. When data writes to the database, the threshold must be >= 2000 ms to prevent a high load on database.

cqlslowlog set_num_slowest_queries

The number of slow queries to keep in-memory.

cqlslowlog recent_slowest_queries

The specified number of the most recent slow queries to retrieve.

cqlsysteminfo enable | disable

Enables collection of CQL system performance information statistics.

dbsummary enable | disable

Enables collection of database summary statistics.

histograms enable | disable

Enables collection of table histograms that measure the distribution of values in a stream of data. Histogram tables provide DSE statistics that can be queried with CQL. The data in the diagnostic histogram tables is cumulative since the DSE server was started.

resourcelatencytracking enable | disable

Enables collection of resource latency tracking statistics.

solrcachestats enable | disable

Enables collection of Solr cache statistics.

solrindexingerrorlog enable | disable

Whether to log Solr indexing errors.

solrindexstats enable | disable

Enables collection of Solr indexing statistics.

solrlatencysnapshots enable | disable

Enables collection of Solr latency snapshots.

solrrequesthandlerstats enable | disable

Enables collection of Solr request handler statistics.

solrslowlog threshold enable | disable

Whether to log the Solr slow sub-query log and set the Solr slow log threshold in milliseconds.

solrupdatehandlerstats enable | disable

Enables collection of Solr update handler statistics.

userlatencytracking enable | disable

Whether to enable user latency tracking.

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.

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

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