Search Topology Limits best practices report by SPDocKit shows whether the search topology component count is within the official Microsoft guidelines.

Search Topology Limits

Issue description

This series of Best Practices shows whether the search topology component count is within the official Microsoft guidelines.

Explanation

Exceeding these limits slows down the communication between search components, which can result in longer query latencies and the search not functioning properly.

SPDocKit Best PracticeMaximum Supported ValueDescription
Analytics Processing Components per Search Service Application6
Analytics Processing Components per Server1
Analytics Reporting Databases4 per Search service applicationThis limit is a threshold and can be exceeded to accommodate specific requirements. Create a new database when the size of any of the existing analytics report databases reaches 250 GB or 20 million rows in total.
Content Processing Components1 per serverAlthough a specific physical host or virtual machine does support multiple content processing components, you achieve better usage of the CPU capacity by using one content processing component.
Crawl Components per Search Service Application16
Crawl Components per Server1
Index Components per Search Service Application60The number of index components is equal to the number of index partitions multiplied by the number of index replicas.
Index Components per Server4The number of index components is equal to the number of index partitions multiplied by the number of index replicas.
Index Partitions25 per Search service applicationAn index partition is a subset of the search index. Increasing the number of index partitions results in each partition holding a smaller subset of the index, reducing the RAM and disk space that is needed on the servers hosting the index components.
Index Replicas3 per index partitionEach index partition can have a set of replicas. Replicas have a positive effect on query performance and it provides better fault tolerance. However, too many replicas per partition can affect indexing performance.
Link Databases4 per Search service applicationThe highest tested number of items a link database can contain is 100 million.
Query Processing Components1 per server
Search Components64 per Search service applicationThis limit does not include crawl components. The sum of all the other search components must stay within this limit.

Solution

Make sure that the number of components in your search topology is within the supported boundaries. To check your search topology, go to Central Administration > Application Management > Manage service applications > Search Service Application.

Additional information

Additional information can be found in the following article: