Performance requirements

MS Access database - installed with the server by default. We recommend this solution when servicing hundreds of clients. However, there is a 2GB size limit for the database. Consequently, you will need to activate cleanups on the server and define an interval (under Tools > Server Options > Server Maintenance) for removing old data.

·	Other databases (MySQL, MSSQL, ORACLE) require a separate installation, but may result in better server performance. It is essential to use suitable hardware for each database engine (mainly ORACLE) following the technical recommendations of its distributor.

If you choose ORACLE as your database solution, you must set the number of cursors higher than the Maximum number of active connections value (under Tools > Server Options > Advanced > Edit Advanced Settings > Advanced; the default is set to 500). The final number of cursors must take into account the number of lower servers, (if replication is used) and cursors that are used by other applications accessing the database engine.

·	Typically, the server's performance is higher when using external databases (i.e. installed on a different physical machine).

The client connection interval is set to 10 minutes by default in ESET Smart Security / ESET NOD32 Antivirus versions 4.2 and later. If you need the client status to update more or less frequently than the default interval, you can change the setting.Keep in mind that a shoerter client connection interval will affect server performance.

Any information sent from client to server is listed under the particular event (e.g. threat log, event log, scan log, configuration change). This parameter cannot be changed directly, but it can be altered if other settings relevant to it are changed. For example, in advanced server configuration (under Tools > Server Options > Server Maintenance) you can setup the maximum amount of logs that can be accepted by the server (this setting includes clients that connect directly as well as replicated clients).In regular operation the long-term average can be estimated at 1 event every 4 hours per client.

·	We strongly recommend using the minimum hardware recommended for your server's operating system, accounting for the number of clients to be serviced.

If a server is overloaded (e.g., we connect 20,000 clients to a server only able to service 10,000 clients at an interval of every 10 minutes) it will skip some of the clients connected. On average every second client connection will be serviced, as if the client connection interval were set to 20 minutes instead of 10 minutes. Every service denial will be logged as follows: "<SERVERMGR_WARNING> ServerThread: maximum number of threads for active connections reached (500), the server will skip this connection. Service denials may also occur during temporary server overloads.

You can change the value under the Maximum number of active connections (the default is 500) in the advanced server settings, but we recommend to do so only in exceptional cases (e.g. when solving specific issues). Should there be an overabundance of system resources and database engine performance you can use this setting to adjust the overall server performance.

During a server's standard operation, we can estimate a client connecting every 10 minutes will report 0.04 events per connection, which is 1 event reported every 4 hours per client. This will produce ~2 kilobytes of traffic per connection.

In a virus outbreak scenario, with a client reporting 7 events every time it connects traffic may increase up to 240 kilobytes per connection. If you use compression (default) the data transferred will be approximately 50% smaller in size, i.e. about 120 kilobytes per connection.

The data includes direct client connections, omitting replicated connections. Replication occurs much less often and serves to send new events from lower servers. Events to be automatically replicated and their verbosity level can be configured in the advanced settings of the server (under Tools > Server Options > Advanced > Edit Advanced Settings > Replication). In the Server maintenance section you can configure the maximum level of logs, that the upper server will accept - this setting applies to both directly connecting clients and replicated clients.

Clean installation of the product with an MS Access database takes up to 60 MB of disk space.

Most of the storage space is taken up by client events, that are stored in the database and to a repository on the disk (default directory is C:\Documents and Settings\All Users\Application Data\Eset\ESET Remote Administrator\Server). ERA requires that at least 5% of the disk be free. If this minimum is exceeded the server will stop receiving some of the client events. This setting can be found under Tools > Server Options > Advanced > Edit Advanced Settings > Advanced > Maximum disk space usage. Approximately 10GB per 1000 clients of free disk space is required for regular operation under the default cleanup settings (deleting events older than 3 months).

A server using an MS Access database that has clients connecting to it every 5 minutes and reporting 7 events (e.g. threat log, event log, scan log, configuration change etc.) per connection in average can temporarily service up to 3000 clients. This scenario depicts a temporary overload situation, such as reporting during a virus outbreak etc.

If the server uses an external MySQL database and the client connection interval is set to 10 minutes (generating 0.02 events per connection) the maximum number of clients the server will be able to service increases to 30,000. Such a scenario exhibits optimal database performance, with clients reporting a relatively small number of events.

In regular operation, using an MS Access database and a client connection interval of 10 minutes enables the server to service a maximum of 10,000 clients.