Setting query service properties

The query service uses a number of environment, logging, and tuning configuration settings.

Procedure

  1. In IBM Cognos Administration, on the Status tab, select Dynamic Cubes.
  2. In the Scorecard section, select the All servers groups view.
    Tip: To select a different view, in the Scorecard section, click the drop-down menu for the current view.
  3. Click the server group under System.
  4. From the Actions menu for the QueryService - dispatcher_name, click Set properties
  5. Click the Settings tab.
  6. In the Value column, type or select the values for the properties that you want to change. The following list describes the properties that you can set for the query service.
    Advanced settings
    Click Edit to specify advanced configuration settings. Because an entry acquires advanced settings from a parent, editing these settings overrides the acquired advanced settings. For information about types of advanced settings, see the IBM Cognos Analytics Administration and Security Guide.
    Dynamic cube configurations
    Click Edit to add dynamic cubes to the query service.
    Audit logging level for query service
    Select the level of logging that you want to use for the query service.
    Enable query execution trace
    A query execution trace (run tree trace) shows queries that run against a data source. You use the trace to troubleshoot query-related issues.
    You can find execution trace logs in the following location: install_location/logs/XQE/reportName/runtreeLog.xml
    You can view and analyze these log files using IBM® Cognos® Dynamic Query Analyzer. For more information, see the IBM Cognos Dynamic Query Analyzer User Guide.
    Enable query planning trace
    Query plan tracing (plan tree) captures the transformation process of a query. You can use this information to gain an advanced understanding of the decisions and rules that are executed to produce an execution tree.
    The query planning trace is logged for every query that runs using dynamic query mode. You can find planning trace logs in the following location: install_location/logs/XQE/reportName/plantreeLog.xml
    Since planning logs are large, there is an impact on query performance when this setting is enabled.
    Generate comments in native SQL
    Specifies which reports are generating the SQL queries in the database.
    Write model to file
    Specifies whether the query service will write the model to a file when a query runs. The file is used only for troubleshooting purposes. Modify this property only with the guidance of IBM Software Support.
    You can find the file in the following location: install_location\logs\model\packageName.txt
    Idle connection timeout
    Specifies the number of seconds to maintain an idle data source connection for reuse.
    The default setting is 300. Valid entries are 0 to 65535.
    Lower settings reduce the number of connections at the expense of performance. Higher settings might improve performance but raise the number of connections to the data source.
    Do not start dynamic cubes when service starts
    Prevents the dynamic cubes from starting when the query service starts.
    Dynamic cube administration command timeout
    Specify the amount of time to wait for a resource to be available for a dynamic cubes administration action. This action is canceled if the time period is exceeded.
    Tip: Setting this value to zero causes the command to wait indefinitely.
    Minimum query execution time before a result set is considered for caching
    Specify the minimum amount of time to wait for a query before caching the results.
    This setting only applies to dynamic cubes.
    Initial JVM heap size for the query service
    Specifies the initial size, in MB, of the Java™ Virtual Machine (JVM) heap.
    JVM heap size limit for the query service
    Specifies the maximum size, in MB, of the JVM heap.
    Initial JVM nursery size
    Specifies the initial size, in MB, that the JVM allocates to new objects. The nursery size is automatically calculated. You do not need to change the setting unless IBM Cognos customer support recommends a change.
    JVM nursery size limit
    Specifies the maximum size, in MB, that the JVM allocates to new objects. The nursery size is automatically calculated. You do not need to change the setting unless IBM Cognos customer support recommends a change.
    JVM garbage collection policy
    Specifies the garbage collection policy used by the JVM. You do not need to change the setting unless IBM Cognos customer support recommends a change.
    Additional JVM arguments for the query service
    Specifies other arguments that control the Java Virtual Machine (JVM). The arguments may vary depending on the JVM.
    Number of garbage collection cycles output to the verbose log
    Specifies the number of garbage collection cycles to be included in the verbose garbage collection. This controls the maximum size of the log file. Consult with IBM Cognos customer support to increase the setting and collect more logs.
    Disable JVM verbose garbage collection logging
    Controls JVM verbose garbage collection logging. You do not need to change the setting unless IBM Cognos customer support recommends a specialized change.
  7. Start or restart the query service.

Results

A summary of the query service properties is displayed in the Settings - Query Service pane.