Apache Solr Reference Guide Covering Apache Solr 6.0

every shard that it knows about, even if it can not communicate with ZooKeeper at the time it receives the
request. This is normally the preferred behavior from a fault tolerance standpoint, but may result in stale or
incorrect results if there have been major changes to the collection structure that the node has not been informed
of via ZooKeeper (ie: shards may have been added or removed, or split into sub-shards)
A zkConnected header is included in every search response indicating if the node that processed the request
was connected with ZooKeeper at the time:
Solr Response with partialResults
{
}
"responseHeader": {
"status": 0,
"zkConnected": true,
"QTime": 20,
"params": {
"q": "*:*"
}
},
"response": {
"numFound": 107,
"start": 0,
"docs": [ ... ]
}
shards.tolerant
In the event that one or more shards queried are completely unavailable, then Solr's default behavior is to fail the
request. However, there are many use-cases where partial results are acceptable and so Solr provides a
boolean shards.tolerant parameter (default ' false'). If shards.tolerant=true then partial results may
be returned. If the returned response does not contain results from all the appropriate shards then the response
header contains a special flag called ' partialResults'. The client can specify ' shards.info' along with the '
shards.tolerant' parameter to retrieve more fine-grained details.
Example response with partialResults flag set to 'true':
Solr Response with partialResults
{
}
"responseHeader": {
"status": 0,
"zkConnected": true,
"partialResults": true,
"QTime": 20,
"params": {
"q": "*:*"
}
},
"response": {
"numFound": 77,
"start": 0,
"docs": [ ... ]
}
Apache Solr Reference Guide 6.0
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