Validate Query API
editValidate Query API
editValidate Query Request
editA ValidateQueryRequest
requires one or more indices
on which the query is validated. If no index
is provided the request is executed on all indices.
In addition it also needs the query that needs to be validated. The query can be built using the QueryBuilders
utility class.
The following code snippet builds a sample boolean query.
Optional arguments
editThe following arguments can optionally be provided:
By default, the request is executed on a single shard only, which is randomly selected. The detailed explanation of
the query may depend on which shard is being hit, and therefore may vary from one request to another. So, in case of
query rewrite the allShards
parameter should be used to get response from all available shards.
When the query is valid, the explanation defaults to the string representation of that query. With rewrite set to true, the explanation is more detailed showing the actual Lucene query that will be executed
Synchronous execution
editWhen executing a ValidateQueryRequest
in the following manner, the client waits
for the ValidateQueryResponse
to be returned before continuing with code execution:
Synchronous calls may throw an IOException
in case of either failing to
parse the REST response in the high-level REST client, the request times out
or similar cases where there is no response coming back from the server.
In cases where the server returns a 4xx
or 5xx
error code, the high-level
client tries to parse the response body error details instead and then throws
a generic ElasticsearchException
and adds the original ResponseException
as a
suppressed exception to it.
Asynchronous execution
editExecuting a ValidateQueryRequest
can also be done in an asynchronous fashion so that
the client can return directly. Users need to specify how the response or
potential failures will be handled by passing the request and a listener to the
asynchronous indices-validate-query method:
The asynchronous method does not block and returns immediately. Once it is
completed the ActionListener
is called back using the onResponse
method
if the execution successfully completed or using the onFailure
method if
it failed. Failure scenarios and expected exceptions are the same as in the
synchronous execution case.
A typical listener for indices-validate-query
looks like:
Validate Query Response
editThe returned ValidateQueryResponse
allows to retrieve information about the executed
operation as follows:
boolean isValid = response.isValid(); int totalShards = response.getTotalShards(); int successfulShards = response.getSuccessfulShards(); int failedShards = response.getFailedShards(); if (failedShards > 0) { for(DefaultShardOperationFailedException failure: response.getShardFailures()) { String failedIndex = failure.index(); int shardId = failure.shardId(); String reason = failure.reason(); } } for(QueryExplanation explanation: response.getQueryExplanation()) { String explanationIndex = explanation.getIndex(); int shardId = explanation.getShard(); String explanationString = explanation.getExplanation(); }
Check if the query is valid or not. |
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Get total number of shards. |
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Get number of shards that were successful. |
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Get number of shards that failed. |
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Get the shard failures as |
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Get the index of a failed shard. |
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Get the shard id of a failed shard. |
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Get the reason for shard failure. |
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Get the detailed explanation for the shards (if explain was set to |
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Get the index to which a particular explanation belongs. |
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Get the shard id to which a particular explanation belongs. |
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Get the actual explanation string. |