Replica: One copy of a shard. Each replica exists within Solr as a core. A collection named “test” created with numShards=1 and replicationFactor set to two will have exactly two replicas, so there will be two cores, each on a different machine (or Solr instance).

What is shard and replica in Solr?

Note: In Solr terminology, there is a sharp distinction between the logical parts of an index (collections, shards) and the physical manifestations of those parts (cores, replicas). In this diagram, the “logical” concepts are dashed/transparent, while the “physical” items are solid.

What are all Solr search replica types?

There are three combinations of replica types that are recommended:

  • All NRT replicas.
  • All TLOG replicas.
  • TLOG replicas with PULL replicas.

What is shards in Solr?

Solr sharding involves splitting a single Solr index into multiple parts, which may be on different machines. When the data is too large for one node, you can break it up and store it in sections by creating one or more shards, each containing a unique slice of the index.

What are collections in Solr?

A collection is a single logical index that uses a single Solr configuration file ( solrconfig. xml ) and a single index schema.

What are cores in Solr?

In Solr, the term core is used to refer to a single index and associated transaction log and configuration files (including the solrconfig. xml and Schema files, among others).

What is core and shard?

Collections are made up of one or more shards. Shards have one or more replicas. Each replica is a core. A single collection represents a single logical index. Follow this answer to receive notifications.

What is indexing in Solr?

Advertisements. In general, indexing is an arrangement of documents or (other entities) systematically. Indexing enables users to locate information in a document. Indexing collects, parses, and stores documents.

What is schema in Solr?

Solr’s Schema API enables remote clients to access schema information, and make schema modifications, through a REST interface. Other features such as Solr’s Schemaless Mode also work via schema modifications made programatically at run time.

What is multivalued Solr?

A multivalued field is useful when there are more than one value present for the field. An easy example would be tags, there can be multiple tags that need to be indexed. so if we have tags field as multivalued then solr response will return a list instead of a string value.

Where is data stored in Solr?

Apache Solr stores the data it indexes in the local filesystem by default. HDFS (Hadoop Distributed File System) provides several benefits, such as a large scale and distributed storage with redundancy and failover capabilities. Apache Solr supports storing data in HDFS.

What is instanceDir in Solr?

instanceDir — The core’s instance directory (i.e. the directory under which that core’s conf/ and data/ directory are located) solr. core. dataDir — The core’s data directory (i.e. the directory under which that core’s index directory are located) solr.

Does Solr need a database?

Almost always, the answer is yes. It needn’t be a database necessarily, but you should retain the original data somewhere outside of Solr in the event you alter how you index the data in Solr. Unlike most databases, which Solr is not, Solr can’t simple re-index itself.