For backward compatibility when reading values, we first check
the ZEEK-prefixed value, and if not set, then check the corresponding
BRO-prefixed value.
Previously, if there was always input in each Process() call, then
the Broker IOSource would never go idle and could completely starve
out a packet IOSource since it would always report readiness with
a timestamp value of the last known network_time (which prevents
selecting a packet IOSource for processing, due to incoming packets
likely having timestamps that are later).
This enables explicit forwarding of events matching a given topic
prefix. Even if a receiving node has an event handler, it will not
be raised if the event was sent along a topic that matches a previous
call to Broker::forward().
Namely these are now removed:
- Broker::relay
- Broker::publish_and_relay
- Cluster::relay_rr
- Cluster::relay_hrw
The idea being that Broker may eventually implement the necessary
routing (plus load balancing) functionality. For now, code that used
these should "manually" handle and re-publish events as needed.
These may be used to change the number of scheduler threads that the
underlying CAF library creates. In pcap mode, it's currently hardcoded
to the minimal 4 threads due to potentially significant overhead in CAF.
Now manually keeps track of peer count instead of querying Broker for
that information (which would result in waiting upon a blocking request
to the core actor).
Broker had changed the semantics of remote logging: it sent over the
original Bro record containing the values to be logged, which on the
receiving side would then pass through the logging framework normally,
including triggering filters and events. The old communication system
however special-cases logs: it sends already processed log entries,
just as they go into the log files, and without any receiver-side
filtering etc. This more efficient as it short-cuts the processing
path, and also avoids the more expensive Val serialization. It also
lets the sender determine the specifics of what gets logged (and how).
This commit changes Broker over to now use the same semantics as the
old communication system.
TODOs:
- The new Broker code doesn't have consistent #ifdefs yet.
- Right now, when a new log receiver connects, all existing logs
are broadcasted out again to all current clients. That doesn't so
any harm, but is unncessary. Need to add a way to send the
existing logs to just the new client.
