Configuring the DA Heartbeat for Frequent Partitions

SAs are required to register with all DAs that support their scopes. A DA can appear after slpd has performed active discovery. If the DA supports slpd scopes, then slpd registers all advertisements on its host with the DA, in order for the set of service advertisements in the scopes to be consistent.

One way slpd discovers DAs is by the initial unsolicited advertisement a DA sends out when it boots. slpd uses the periodic unsolicited advertisement (the heartbeat) to determine whether a DA is still active, and removes the DAs it uses and offers to UAs if a heartbeat fails to appear.

Finally, when a DA undergoes a controlled shutdown, it transmits a special DA advertisement that informs listening SA services that it will be out of service. slpd also uses this advertisement to remove inactive DAs from the cache.

If your network is subject to frequent partitions and SAs are long-lived, slpd can remove DAs from its cache during the partitions if heartbeat advertisements are not received. By decreasing the heartbeat time, you can decrease the delay before a deactivated DA is restored to the cache after the partition is repaired.

The net.slp.DAHeartBeat property controls how often a DA multicasts an unsolicited DA advertisement. By default, the DA heartbeat period is set to 3 hours (10800 seconds). The following entry decreases the DA heartbeat value to one hour:

net.slp.DAHeartBeat=3600