update API , as shown in Figure 11, “Partial updates to a document”, combines the read and
write patterns explained previously.
Here is the sequence of steps used to perform a partial update on a document:
The client sends an update request to
It forwards the request to
Node 3, where the primary shard is allocated.
Node 3retrieves the document from the primary shard, changes the JSON in the
_sourcefield, and tries to reindex the document on the primary shard. If the document has already been changed by another process, it retries step 3 up to
retry_on_conflicttimes, before giving up.
Node 3has managed to update the document successfully, it forwards the new version of the document in parallel to the replica shards on
Node 2to be reindexed. Once all replica shards report success,
Node 3reports success to the coordinating node, which reports success to the client.
update API also accepts the
timeout parameters that are explained in Creating, Indexing, and Deleting a Document.