Monitor Search Server Health with Load Balancers

To enable external load balancers to monitor the health of Exalead CloudView search servers, specify an isAlive query. Then run this query at regular intervals to verify that its target indexes are still available. When the query fails, the status changes to "not alive".

You can also configure load balancers to check HTTP return error code:

  • 200 = alive

  • Any other value = not alive

This task shows you how to:

See Also
Troubleshoot Search Performance
Display Query Statistics Using a Simple Search Request

Monitor Both the Search API and the Mashup UI

Context: This checks that both the Search API and the Mashup UI are working correctly, by sending a lightweight query at regular intervals.

  1. Go to Mashup Builder and select Application > Application properties.
  2. In isAlive query, enter your test query. For example, /page/<page>?q=gizmo (replace gizmo with your own query term).

    Important: This query is regularly sent to all indexes associated with this application. To avoid impacting performance, specify a simple query that returns few, if any, matching documents.

  3. Click Save and then apply your changes.
  4. On your load balancer, enter this URL to monitor search server health: http://<HOSTNAME>:<BASEPORT>/mashup-ui/isAlive.

Monitor the Search API Only

Before you begin: If your deployment uses a custom search application created through the Search API, instead of the Mashup UI, modify the SearchCommand to include one or more isAlive queries. You need to push a document that matches this query.
  1. Open <DATADIR>/config/SearchAPI.xml.
  2. Modify <SearchCommand> to include the <isAliveQueries> nested element, as shown below (replace foobar with your query term). 
    <SearchCommand isAliveAsynchronousDelayS="5" isAliveSynchronous="true" enableSOAP="false"
            maxConcurrentQueries="10" targetReporting="search-api" defaultTarget="st0" defaultLogic="sl0"
            base="/search-api"> 
<isAliveQueries> 
<ns2:StringValue value="q=foobar"/> 
</isAliveQueries> 
</SearchCommand>
    Important: This query is regularly sent to all search servers associated with this application. To avoid impacting performance, specify a simple query that returns few, if any, matching documents.
  3. (Optional) Add additional StringValue elements for additional queries.
  4. Apply changes manually. See Installing Secondary Servers.
  5. On your load balancer, enter this URL to monitor search server health: http://<HOSTNAME>:<BASEPORT+10>/search-api/isAlive.