Execution slots

The scheduler manages a number of slots in which tasks can be executed in parallel. The maximum number of concurrent slots is determined for each category of tasks as described in the following table.

Note: For an overview of the flow elements belonging to each of these categories, refer to Switch performance tuning.

Task category

Task types in this category

Maximum concurrent slots for this category

Disk

File handling tasks, such as copying & moving jobs

5

Network

Network transfer tasks, including FTP send/receive, Mail send/receive, Checkpoint via mail.

Determined by the value of "Concurrent network transfer tasks" preference (See Switch preferences: Processing)

Processor

File processing tasks, executed by configurators and apps and flow elements such as archive, unarchive, 'heavy' scripts,... Note that light scripts belong to a separate category (see paragraph below).

Determined by the value of "Concurrent processing tasks" preference (See Switch preferences: Processing)

Light

Light scripts used in the Script element (see paragraph below)

Minimum: 5

Maximum: 3 + value of "Concurrent processing tasks" preference (See Switch preferences: Processing)

TimerFired

Any TimerFired entry point invocation

Minimum: 2

Maximum: twice the value set of "Concurrent processing tasks" preference (See Switch preferences: Processing)

Within each category concurrency is further limited by the serialization needs of each task type. Thus even when a slot is available for a particular category, a task in that category may not match the slot because, for example, another task of the same type is already executing and the task type has the serialized execution mode.

Light and heavy scripts

Scripts include many of the tools built-in to Switch, and all third-party script packages.

Initially a script is heavy. If its entry points consistently complete quickly (in less than 1 second for 5 consecutive times) the script becomes light, until it violates this "trust" by not completing within 1 second once – it then becomes heavy again.