System Control

System Control

The System Control allow an administrator to free memory, clear class caches, view session information and much more.

Memory

The Memory segment shows system internal memory usage information.

Memory segment fields

Memory segment buttons

User and session information

The user and session information segment shows detailed server, user and session information.

User and session information fields

User and session information buttons

Logical Unit Of Work (LUOW) tracking

In a transactional system, there are some sets of work that you want saved either in its entirety, or not at all. A logical unit of work (luow) is a set of transactions where either all sets are successfully applied against the database, or no sets have any impact on the database.

For different reasons a luow can end up in a state of neither committed nor roll backed. In such cases it is of great value to be able to track open luow:s and to act on them. The logical unit of work tracking portlet gives you the possibility to track open LUOWs.

Pressing the Luow tracking… button will take you to the System Control luow tracking portlet as below:

Luow portlet fields

Luow portlet buttons

A right click on a specific luow will present two different options:

Rollback: Performs a rollback of the selected luow transaction.

Stack trace: Performs a stack trace for a specific open luow and populates the Trace field with the result.

Sql tracking

In the sql tracking view you have the possibility to see erroneous sql operations. Such problems are often caused by failed logical unit of work operations.

Pressing the Sql tracking… button will take you to the System Control sql tracking portlet as below:

Sql tracking portlet fields

A right click on a specific open result set will present two different options:

Remove: Removes an open result set

Stack trace: Performs a stack trace for a specific open result set and populates the Trace field with the result.

Cache

The cache segment of the System Control main portlet provides cache information for a number of different cached classes.

Cache size settings are system default set. These settings can be overridden if specified in the sitedef. No settings can be altered in runtime!

Cache segment fields.

A right click on a specific class will present two different options:

Clear cache: Removes all cashed objects from the cache

Calculate memory utilization: Calculates the amount of memory that the cached class uses and populates the Memory utilization field with the calculated value

Planned shutdown

The planned shutdown segment allows you to broadcast a message to all logged in users about a server shutdown.

Perform the following steps to broadcast a planned shutdown message:

Set the scheduled shutdown time.

Enter the estimated time the server will be down (duration).

Press the set button.

This will automatically generate a message that will be shown in each users session.

Note that you still need to manually bring down the server. Scheduling the shutdown simply allows all users to be notified that the server will be shutdown for some time.

Connections

Database operations require Comflow programs to acquire jdbc connections from a pool of connections. For different reasons it might happen that an established jdbc connection does not get released. The connections view offers the possibility to view and act upon such active connections.

Listed in the connection segment are all services (see the Name field description in Table 14). Each service shows the number of active and idle connections to it. If the number of active connections remains at a high level even as users log off, it may point to potential problems with SQL statements not being closed correctly, so is worthwhile monitoring.

Connection segment fields

A right click on a specific connection will present three different options:

Enable tracking: Enables tracking for a specific connection

Disable tracking: Disables tracking for a specific connection

Details: Leads to a detailed view of a specific connection

Acting upon active connections

Suppose I have a number of active connections that I suspect should have been closed and that I now want to trace and manually disable.

1. Enable tracking by right clicking on the connection and choose Enable tracking as below:

Row click the connection or right click and choose Details

In this example there are ten active connections. From the Trace field we can see that the active connections all come from the same JAVA class.

A right click on a trace entry will give you two options; Release or Stack trace as below.

Choosing “Stack trace” on an active connection will give you a full stack trace:

Choosing “Release” on an active connection will release the selected open connection.

Databases

In the databases segment you have the possibility to view all sitedef defined databases.

The concept of a database in this context should not be confused with a database that is running on a server. The Pool field in Figure 20 is a good example of this because it shows that several databases can actually run on one schema in one database (see Name explanation in Table 14)!

Database portlet fields

Loggers

This segment allows you to control the level of logging for various categories at runtime. Note that the default logging level for each category is defined in the sitedef. A runtime server restart will set all logger levels to the sitedef default settings.

The logger level can be set to either:

FATAL

ERROR

WARN

INFO

DEBUG

FATAL will show the least amount of logging, while DEBUG the most.

Loggers