Query Service Administration - IBM Cognos

A vital part of running and maintaining a successful IBM Cognos implementation is administration. By this we mean that knowing exactly what is going on in your system at any time and reacting to those events appropriately is essential for you to get the most out of your IBM Cognos investment. IBM Cognos Administration allows for easy monitoring, configuring, and tuning of services that are available in the IBM Cognos instance. With the addition of Dynamic Query Mode, exposed as the Query Service in IBM Cognos Administration, new metrics and tuning options are added,

IBM Cognos Administration
IBM Cognos Administration

Query Service metrics

You can monitor and configure the Query Service status and its thresholds, a starting point of a new state, in IBM Cognos Administration by opening the Metrics pane for the respective service. By default, all metrics record performance information, but no thresholds are configured because acceptable threshold values depend on the IBM Cognos operating environment and need to be configured accordingly.

You can define the thresholds for the following Query Service metrics:

  • Last response time: The time taken by the last successful or failed request
  • Number of failed requests: The number of service requests where a fault was returned
  • Number of processed requests: The number of processed requests
  • Number of successful requests: The number of service requests where no fault was returned
  • Percentage of failed requests: The percentage of processed requests thatfailed
  • Percentage of successful requests: The percentage of processed requests that succeeded
  • Response time high watermark: The maximum length of time taken to process a successful or failed request
  • Response time low watermark: The minimum length of time taken to process a successful or failed request
  • Seconds per successful request: The average length of time taken to process a successful request
  • Service time: The time taken to process all requests
  • Service time failed requests: The time taken to process failed requests
  • Service time successful requests: The time taken to process successful requests
  • Successful requests per minute: The average number of successful requests processed in one minute You can also create an agent that notifies you when thresholds are exceeded. Sample agents that monitor the audit database for threshold violations and perform common actions when violations are detected are included in the audit samples package.

Manage the cache in IBM Cognos Administration

To increase the performance of recurring reports and to minimize the load on underlying data sources, Dynamic Query Mode includes a self-learning in-memory cache. The query mode can store the data cache in memory as long as needed. One side effect that stems from caching metadata and data request on an ever-changing data source is the possibility that the data that is contained in the cache has become old and stale. This issue leads to reports that do not display the most recent data. To help overcome this issue, IBM Cognos Administration includes flexible cache maintenance features. You can locate the first feature by clicking Configuration Query ServiceCaching

Query Service Caching
Query Service Caching

This new entry in the IBM Cognos Administration tool allows the administrator to clear the cache and write cache statistics to file on a Server Group basis in a ad-hoc fashion. After this task runs, all report servers in the selected server group that host a Query Service clear the cache or dump the statistics to a file. If you write the cache statistics disk, a new file is created in the ../logs/XQE/ folder on all IBM Cognos servers in that particular server group that host an instance of the Query Service. The file name adheres to the following template:

Example shows an example of this file.

Server group cache statistics file

Figure shown an example of the content of this file.

Cache state
Cache state

This example illustrates a cache state that contains metrics for a package called DQM_GODB - DAN. This package is based of the GODB cube using the Essbase data source Essbase_DAN.

Under the Cache Metrics comment, notice that for this package, 285 query requests were issued with five requests not being fulfilled by the package cache. Other than clearing the cache per Server Group, you can now also create or schedule Query Service Administration tasks. You can locate these tasks by clicking Configuration Content Administration

Query Service Administration task
Query Service Administration task

The cache maintenance tasks that you can create are the same as under the Query Service Caching section, with the only difference being the granularity. You can schedule these tasks to clear or to write statistics to file based on data source, catalog, and cube After this task runs, all report servers that host a Query Service clear the cache or dump the statistics to file.

Query Service Administration task options
Query Service Administration task options

You can determine the values that you need to enter here by examining Figure. For example, a task that is clearing the cache will dump a file according to the following template as shown in Example.

Individual cache statistics file

Query Service settings

In addition to the cache maintenance dialog boxes, there is another area in IBM Cognos Administration that deals with the administration of the Query Service. This dialog box allows you to modify logging information and connection time-out. You can locate this dialog box by clicking Configuration Dispatchers andServices Query Service properties as

Query Service properties
Query Service properties

Figure shows the Settings tab within this dialog box.

Query Service settings
Query Service settings

The Settings tab allows you to modify the following settings:

  • Audit Logging level
    Controls the amount of audit information that is recorded for this service. The higher you set the logging level, the more it degrades system performance.
  • Query execution trace
    This switch toggles the recording of the run tree or also known as the query execution phase.
  • Query plan trace
    This switch toggles the recording of the plan tree or also known as the query planning phase.

Figure shows where in IBM Cognos Configuration you can disable the Query Service to give those expensive resources back to the system.

Disable the Query Service
Disable the Query Service

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