zcm_broker

zcm broker commands

Check broker status:

./build/tools/zcm broker ping

Stop broker:

./build/tools/zcm broker stop

List broker registry:

./build/tools/zcm broker list

zcm_broker daemon

Run broker main loop:

./build/tools/zcm_broker

Broker resolution for zcm_broker:

• Optional explicit override:
  • ZCMBROKER or ZCMBROKER_ENDPOINT (takes priority)
• ZCMDOMAIN selects the domain
• ZCmDomains is read from:
  • $ZCMDOMAIN_DATABASE or $ZCMMGR, else
  • $ZCMROOT/mgr
• ZCmDomains stands for the zCm domain registry file:
  • one line per domain
  • each line defines broker endpoint and dynamic data-port allocation range
• Why this is convenient on non-broadcast networks:
  • discovery is file-based (no multicast/broadcast dependency)
  • all nodes read the same broker/port-range mapping
  • with a shared network file server, configuration stays consistent across hosts
  • in segmented/restricted networks this gives deterministic startup and lookup
• Who uses it:
  • zcm_broker (startup endpoint/range)
  • zcm broker ping|stop|list (broker lookup)
  • all zcm commands (names, ping, send, kill, ...)
  • zcm_proc startup/registration and runtime data-worker port allocation
• Line format:
  • <domain-name> <broker-host> <broker-port> <port-range-start> <port-range-size>
  • Example:
    • myplace 127.0.0.1 5555 7000 100
• Field meanings:
  • domain-name: lookup key selected by ZCMDOMAIN.
  • broker-host: host/IP used to build tcp://<broker-host>:<broker-port>.
  • broker-port: broker bind/lookup port.
  • port-range-start: first port in the dynamic bind window used by zcm_proc.
  • port-range-size: number of ports in that dynamic bind window.
  • defaults for zcm_proc bind window when missing/invalid:
    • port-range-start=7000
    • port-range-size=100

No trailing repository/repo field is used by runtime components.

Broker startup behavior:

• zcm_broker binds on the selected port using the local machine address.
• After successful startup, it updates the current ZCMDOMAIN row in ZCmDomains:
  • broker-host -> detected local IPv4/hostname
  • broker-port -> active broker port
  • row is normalized to 5 fields:
    • <domain-name> <broker-host> <broker-port> <port-range-start> <port-range-size>

Broker runtime environment variables:

Variable	Meaning
ZCM_BROKER_REMOTE_PROBE_INTERVAL_MS	Interval for remote registration liveness probes (default 3000, valid 250..120000).
ZCM_BROKER_REMOTE_PROBE_FAILS	Consecutive failed probes before dropping a stale remote entry (default 3, valid 1..20).
ZCM_BROKER_TRACE_REG	When truthy, enables register/unregister trace logs (0/false/no disables).