State Server

To improve fault tolerance, each configuration can have a BI servers cluster implemented. If two or more BI servers are used, it is recommended to add a state server to configuration, which will restore object parameters in case of failure of the requested BI server.

As a state server, the platform supports work with Redis and Memcached. In order a Memcached-based state server works, install OpenSSL libraries.

To use a state server in the platform, one should determine additional settings. See the required subsection:

Working with BI server, after executing queries to change objects, their states (moniker and parameters required to restore the object) are saved at the state server and loaded from the server on further addressing the objects. Saving states is supported by the security manager and various repository objects.

Repository connection settings and repository links (repository description and credentials used for connection).
Express reports.
Dashboards.
Regular reports.
Workbooks.
Data sets.
All types of dictionaries, and also related objects (selection schemas, groups of elements, alternative hierarchies).
Cubes and time series databases.
ETL task.
Workspace.
Data entry forms, Calculation algorithms, Business process management, Business application designers.
DBMS commands, Procedure.
The types of objects specified above created in BI server memory but not yet saved in the repository.

Recommendations

To provide continuous work of BI server, make sure that the state server is available. To set up and start the state server, use recommendations of Redis/Memcached developers taking into account the size of the created system.

Work Issues

If issues occur during communication between the platform and the state server, connection loss, freeze of system components, analyze logs of BI server and state server. In case of difficulties with issue solving, contact technical support by sending a request to support@fsight.ru or technical support services that are available after registration at the website.

Description

Platform operations result in the error "The MemCached state server is unavailable. Check connection settings for the state server".

Cause

By default, MemCached uses memory fragments, in which information with size 1 Mb is saved.

In the platform, when creating a block of information saved to the MemCached state server and required for object restoring, the obtained block size exceeds 1 Mb.

Solution

To resize the memory fragment, use the "-I <N bytes>" key during MemCached start, one can also use the K and M suffixes to specify the size in kilobytes and megabytes.

It is not recommended to increase memory fragment size without necessity because this directly affects system performance and the amount of memory required for work.

The example:

MemCached -I 2M