Distribute IDOL Actions

The main function of the DAH is to distribute actions to its child servers to query them. The DAH can distribute different actions depending on whether you run it in mirror or non-mirror mode:

DetectLanguage Query
DocumentStats Suggest
GetContent SuggestOnText
GetQueryTagValues Summarize
GetTagNames TermExpand
GetTagValues TermGetBest
Highlight TermGetInfo

In addition, you can use some actions to query the DAH for information about its operation (for example, to return a list of requests that were sent to the DAH, or to return license information). For details of supported actions and action parameters, refer to the Distributed Action Handler Reference.


For the LanguageSettings action, when the child servers have compatible language configurations, DAH returns the child server response, except for the LanguageDirectory configuration. The child server language configuration must be the same for all child servers, except for LanguageDirectory. If the child server configuration is not compatible, DAH returns the message Engines returned inconsistent information.

Return Child Server Information

For the following actions, you can use the PrintEngine action parameter to return additional information for each result document that shows the child server that the result comes from.


When you set PrintEngine to True for these actions, the response includes an <autn:engines> tag for each result, which includes the child server information in the format X[.Y.Z...], where:

For example, if you have a DAH, with a layer of sub-DAHs, and then a layer of child IDOL Servers, a value of 3.2 for <autn:engines> represents a document coming from child server 2 of sub-DAH 3 of the top level DAH.