WAIT FOR EVENT - Have Slonik script wait for previous event to complete

Waits for event Confirmation. Slonik remembers the last event generated on every node during script execution (events generated by ear‐ lier calls are currently not checked). In certain situations it is necessary that events generated on one node (such as CREATESET) are processed on another node before issuing more commands (for instance, SLONIKSUBSCRIBESET(7)). WAITFOREVENT may be used to cause the slonik script to wait for confirmation of an event, which hopefully means that the subscriber node is ready for the next action. WAITFOREVENT must be called outside of any try block in order to work, since new confirm messages don't become visible within a transaction. ORIGIN = ival | ALL The origin of the event(s) to wait for. CONFIRMED = ival | ALL The node ID of the receiver that must confirm the event(s). WAIT ON = ival The ID of the node where the “sl_confirm” [not available as a man page] table is to be checked. TIMEOUT = ival The number of seconds to wait. Default is 600 (10 minutes). TIMEOUT=0 causes the script to wait indefinitely.

WAIT FOR EVENT ( ORIGIN = ALL, CONFIRMED = ALL, WAIT ON = 1 );

No application-visible locking should take place.

WAIT FOR EVENT - Have Slonik script wait for previous event to complete

Not all events return interesting results. For instance, many people have run afoul of problems with SLONIKSUBSCRIBESET(7), when subscribing a new set. Be aware (and beware!) that a SLONIKSUBSCRIBESET(7) request will return the event confirmation almost immediately, even though there might be several hours of work to do before the subscription is ready. The trouble with SLONIKSUBSCRIBESET(7) is that it is processed as two events, one on the origin node, with a second event, to enable the subscription, on the subscriber. In order to more reliably monitor from within a slonik(1) script that SLONIKSUBSCRIBESET(7) is com‐ plete, you may submit a SLONIKSYNC(7) event after the subscription, and have the WAIT request wait on the SYNC event, as follows. # Assuming that node 1 is the origin for set 999 that has direct subscribers 2 and 3 SUBSCRIBE SET (ID = 999, PROVIDER = 1, RECEIVER = 2); WAIT FOR EVENT (ORIGIN = 1, CONFIRMED = ALL, WAIT ON=1); SUBSCRIBE SET (ID = 999, PROVIDER = 1, RECEIVER = 3); WAIT FOR EVENT (ORIGIN = 1, CONFIRMED = ALL, WAIT ON=1); MERGE SET ( ID = 1, ADD ID = 999, ORIGIN = 1 ); 19 September 2024 SLONIKWAITFOREVENT(7)

This command was introduced in Slony-I 1.0 In version 2.0, the default value for WAITON was removed, so a node must be specified.