Indexer Test

Indexers manage the content to be included in an index, and propagate that content to query servers where they are stored in index files.

Each item that a connector submits for indexing passes through the indexing pipeline, in which a predefined set of modules manipulates the items one by one. At the end of this, the FIXML needed for indexing is produced and handed over to the indexer by the Indexing Dispatcher. The Indexer receives the item and creates binary indexes in the data folder on disk. These binary indexes are then sent to the query matching component and are used during query evaluation during searching.

If too many feeding operations/documents are sent to an indexer for processing, that indexer may be forced to push many of these operations into the API queue, where they will be held until they are taken up for processing. Administrators need to monitor the length of this queue at frequent intervals to determine the processing power of an indexer. Using the Indexer test, administrators can keep an eye on the number and nature of documents that each indexer processes, track the growth of the API queues, monitor the FiXML fill rate of every indexer, and thus promptly capture potential overloads, processing delays, processing failures, and other inefficiencies in the functioning of every indexer.

Target of the test : A FAST Search Server 2010 for SharePoint

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every indexer configured on the FAST Search Server 2010 for SharePoint farm.

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed

Host

The host for which the test is to be configured.

Port

Refers to the port used by the specified host. By default, this is 13280.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Total number of feed operation

Indicates the total number of feed operations processed by this indexer.

Number

The measure indicates the total number of items that are indexed and updated.

API operations processed

Indicates the rate at which the feed operations are processed by this indexer.

Operations/Sec

A consistent decrease in the value of this measure could indicate a processing bottleneck.

API partial update operations

Indicates the number of feed operations processed by this indexer that are partial update operations.

Number

 

API queue load

Indicates the current load on the API queue of this indexer.

Bytes

The API queue is used by the indexer to hold pending operations waiting to be persisted.

The value of this measure is obtained by the ratio of the current size of the API queue to the maximum size of the API queue. A low value is desired for this measure.

API queue size

Indicates the number of batches that are currently in the API queue of this indexer.

Number

Indexers queue incoming work under high load. This is common, especially for partial updates. If API queues never (intermittently) reach zero, the indexer is the bottleneck. The crawler will pause when the queue reaches 256MB in one of the indexers. This can occur if the storage subsystem is not sufficiently powerful. It will also occur during large redistribution of content between partitions, which temporarily blocks more content from being indexed.

API remove operations

Indicates the number of feed operations processed by this indexer that are remove operations.

Number

 

API status update operations

Indicates the number of feed operations processed by this indexer that are status updates.

Number

 

API remove collection operations

Indicates the number of feed operations processed by this indexer that are remove collection operations.

Number

 

Documents in indexer

Indicates the total number of valid items that are currently contained in the docindex of this indexer.

Number

The docindex is a mapping to the persisted items on disk, so this translates to the number of valid items persisted on disk (FiXML).

API update operations

Indicates the number of feed operations processed by this indexer that are add/update operations.

Number

 

API failed operations

Indicates the number of feed operations that were not successfully processed by this indexer.

Number

 

Fixml fill rate

Indicates the ratio of the number of valid items in a persisted file to the total number of persisted items.

Percent

FiXML files (internal item storage in the indexers) are compacted regularly, by default between 3am and 5am every night. Low FiXML fill rate (<70%) will lead to inefficient operation.

Last batch size

Indicates the size of the previous batch that was processed by this indexer.

Bytes

 

Maximum batch size

Indicates the size of the largest batch that was processed by this indexer during the last measurement period.

Bytes

 

Maximum documents per sec

Indicates the maximum number of items that were indexed by this indexer in an index job per second.

Indexed/Sec

By closely observing variations to these measures over time, you can proactively detect potential processing latencies.

Minimum documents per sec

Indicates the minimum number of items that were indexed in an index job per second.

Number

Number of file receivers currently registered

Indicates the total number of file receivers that are currently registered on this indexer.

Number

The file receivers can either be backup indexers or search controllers.

Number of search controllers currently registered

Indicates the total number of search controllers that are currently registered on this indexer.

Number

The registered search controllers get new indices from over the indexer.

Search controller stubs currently allocated by the indexer

Indicates the total number of search controller stubs that are currently allocated by this indexer.

Number

The search controller stub is used to communicate with a remote search controller.

This measure is a good indicator of the number of search controllers that are communicating with the indexer.

Search controller allocated count

Indicates the number of times a search controller has been allocated on this indexer.

Number

 

Size of documents

Indicates the size of all the valid items that are persisted on the disk.

Bytes