maxReconnectAttempts=0 relates to the use of failover only, where you use failover to choose between a list of broker urls (typically a pair for master slave). masterSlave sets maxReconnectAttempts=0 on the underlying failover url. The static discovery, which is implemented by the SimpleDiscoveryAgent can do retries and backoff etc. see: https://github.com/apache/activemq/blob/d54e0d6ab590b6a6148a5e2629c45b95d3f40eb8/activemq-client/src/main/java/org/apache/activemq/transport/discovery/simple/SimpleDiscoveryAgent.java#L42
The network bridge is a discovery listener, it gets told to add/remove services (urls) that are discovered/retried. On 24 September 2014 20:20, Tim Bain <tb...@alumni.duke.edu> wrote: > Gary, Torsten, and others have said in various places that broker-to-broker > networkConnectors should set maxReconnectAttempts=0 to allow reconnection > to be handled by the network bridge. (Sources: 1 > < > http://tmielke.blogspot.com/2011/09/activemq-network-bridge-to-masterslave.html > >, > 2 > < > http://activemq.2283324.n4.nabble.com/Persistent-messages-disappearing-td4681353.html > >, > 3 > < > http://grokbase.com/t/activemq/users/1427v9eqkf/prioritybackup-not-supported-with-masterslave > >) > Torsten (link 1) was talking about static: network connectors, while Gary's > quotes in the other two links were related to failover: (or masterslave:, > which is just chrome on top of failover:), but if it's a requirement of the > network bridge that it be the one to re-establish the question, it > shouldn't matter what the underlying transport is. > > It's obvious in FailoverTransport > < > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.activemq/activemq-client/5.10.0/org/apache/activemq/transport/failover/FailoverTransport.java#FailoverTransport > > > how maxReconnectAttempts=0 gets processed to mean "don't try to reconnect", > allowing the network bridge to re-establish the connection, and there are > notes in http://activemq.apache.org/failover-transport-reference.html > explaining that this interpretation of the value "0" was implemented in > 5.6.0 (https://issues.apache.org/jira/browse/AMQ-3542). There's no > similar > code in SimpleDiscoveryAgent > < > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.activemq/activemq-all/5.10.0/org/apache/activemq/transport/discovery/simple/SimpleDiscoveryAgent.java#SimpleDiscoveryAgent > > > (which handles connection attempts for the static: transport > <http://activemq.apache.org/static-transport-reference.html>, as I > understand it) to interpret "-1" as "reconnect forever" and "0" as "don't > reconnect". > > Is Gary's and Torsten's advice about maxReconnectAttempts not applicable to > static: network connectors for some reason that I'm not understanding? Or > should the changes Gary made in AMQ-3542 have been applied to all protocols > that include reconnection attempts? (Do I need to open a JIRA for this?) > > And a related question: when using the static: transport to establish a > broker mesh, if we set maxReconnectAttempts=0, is there a way to perform > exponential backoff at the network bridge, so it doesn't continually try to > reconnect (and spam the logs) when one broker in the mesh is offline for a > while? The only way I see to control exponential backoff is within the > static: transport via the useExponentialBackOff=true option; searching the > source code (I'm looking at 5.8.0), I don't see any references to > exponential backoff in any code that seems to be related to network > bridges... > > Thanks, > Tim > -- http://redhat.com http://blog.garytully.com
