ReindexRequest can be used to copy documents from one or more indexes into a
It requires an existing source index and a target index which may or may not exist pre-request. Reindex does not attempt to set up the destination index. It does not copy the settings of the source index. You should set up the destination index prior to running a _reindex action, including setting up mappings, shard counts, replicas, etc.
The simplest form of a
ReindexRequest looks like this:
dest element can be configured like the index API to control optimistic concurrency control. Just leaving out
versionType (as above) or setting it to internal will cause Elasticsearch to blindly dump documents into the target.
versionType to external will cause Elasticsearch to preserve the version from the source, create any documents
that are missing, and update any documents that have an older version in the destination index than they do in the
create will cause
_reindex to only create missing documents in the target index. All existing
documents will cause a version conflict. The default
By default version conflicts abort the
_reindex process but you can just count
them instead with:
You can limit the documents by adding a query.
It’s also possible to limit the number of processed documents by setting
_reindex uses batches of 1000. You can change the batch size with
Reindex can also use the ingest feature by specifying a
If you want a particular set of documents from the source index you’ll need to use sort. If possible, prefer a more selective query to maxDocs and sort.
ReindexRequest also supports a
script that modifies the document. It allows you to
also change the document’s metadata. The following example illustrates that.
ReindexRequest supports reindexing from a remote Elasticsearch cluster. When using a remote cluster the query should be
specified inside the
RemoteInfo object and not using
setSourceQuery. If both the remote info and the source query are
set it results in a validation error during the request. The reason for this is that the remote Elasticsearch may not
understand queries built by the modern query builders. The remote cluster support works all the way back to Elasticsearch
0.90 and the query language has changed since then. When reaching older versions, it is safer to write the query by hand
ReindexRequest also helps in automatically parallelizing using
setSlices to specify the number of slices to use.
ReindexRequest uses the
scroll parameter to control how long it keeps the
"search context" alive.
In addition to the options above the following arguments can optionally be also provided:
When executing a
ReindexRequest in the following manner, the client waits
BulkByScrollResponse to be returned before continuing with code execution:
BulkByScrollResponse bulkResponse = client.reindex(request, RequestOptions.DEFAULT);
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
5xx error code, the high-level
client tries to parse the response body error details instead and then throws
ElasticsearchException and adds the original
ResponseException as a
suppressed exception to it.
ReindexRequest 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 reindex method:
The asynchronous method does not block and returns immediately. Once it is
ActionListener is called back using the
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
reindex looks like:
It is also possible to submit a
ReindexRequest and not wait for it completion with the use of Task API. This is an equivalent of a REST request
with wait_for_completion flag set to false.
ReindexRequest reindexRequest = new ReindexRequest(); reindexRequest.setSourceIndices(sourceIndex); reindexRequest.setDestIndex(destinationIndex); reindexRequest.setRefresh(true); TaskSubmissionResponse reindexSubmission = highLevelClient() .submitReindexTask(reindexRequest, RequestOptions.DEFAULT); String taskId = reindexSubmission.getTask();
BulkByScrollResponse contains information about the executed operations and
allows to iterate over each result as follows:
TimeValue timeTaken = bulkResponse.getTook(); boolean timedOut = bulkResponse.isTimedOut(); long totalDocs = bulkResponse.getTotal(); long updatedDocs = bulkResponse.getUpdated(); long createdDocs = bulkResponse.getCreated(); long deletedDocs = bulkResponse.getDeleted(); long batches = bulkResponse.getBatches(); long noops = bulkResponse.getNoops(); long versionConflicts = bulkResponse.getVersionConflicts(); long bulkRetries = bulkResponse.getBulkRetries(); long searchRetries = bulkResponse.getSearchRetries(); TimeValue throttledMillis = bulkResponse.getStatus().getThrottled(); TimeValue throttledUntilMillis = bulkResponse.getStatus().getThrottledUntil(); List<ScrollableHitSource.SearchFailure> searchFailures = bulkResponse.getSearchFailures(); List<BulkItemResponse.Failure> bulkFailures = bulkResponse.getBulkFailures();
Get total time taken
Check if the request timed out
Get total number of docs processed
Number of docs that were updated
Number of docs that were created
Number of docs that were deleted
Number of batches that were executed
Number of skipped docs
Number of version conflicts
Number of times request had to retry bulk index operations
Number of times request had to retry search operations
The total time this request has throttled itself not including the current throttle time if it is currently sleeping
Remaining delay of any current throttle sleep or 0 if not sleeping
Failures during search phase
Failures during bulk index operation