#2579 imm: remove disconnected appliers

[Zoran Milinkovic]

Once an implementer is created, it resides in the system to the cluster restart. There is no way to remove implementers from the system.
Applier is a special case of implementers and the same feature applies to appliers.

When OpenSAF is runnning in the cloud, nodes are added and are removed from the system, and new nodes may come with new names.
This makes a problem with appliers, which in most cases contain a node name in an applier name.
If there are a lot of adding and removing nodes, it can come in the situation that all 3000 implementers are allocated, and intialization of new implementers or appliers is not possible.

Since there are a limited number of implementers, there is no need to remove implementers from the system.
IMM should remove appliers from the system if they are not used for a certain time.

If SC absence allowed is enabled, this time should not be less that SC absence allowed time. Otherwise all appliers will be discarded when the system comes back from the headless state.

[Zoran Milinkovic]

https://sourceforge.net/p/opensaf/mailman/message/36033957/

[Zoran Milinkovic]

commit 959c04b78346991bcffa75d1e4774d3610413e6e
Author: Zoran Milinkovic zoran.milinkovic@ericsson.com
Date: Mon Sep 11 17:46:23 2017 +0200

imm: remove disconnected appliers [#2579]

When an applier is disconnected, it will be removed from the system after time period set in minApplierTimeout attribute in IMM object.
If the time is set to 0, it will work as it works today, and it will never be removed from the system.

The time set in minApplierTimeout attribute guarantees that the applier will be "alive" for at least the time set in the attribute.
When this period expires, with the next clean the basement call, the applier will be removed.

The time set in minApplierTimeout attribute is in seconds.

To enable this feature, protocol51710 must be enabled and minApplierTimeout attribute value must be great than 0.