flux start [OPTIONS] [initial-program [args...]]
flux-start(1) launches a new Flux instance. By default, flux-start execs a single flux-broker(1) directly, which will attempt to use PMI to fetch job information and bootstrap a flux instance.
If a size is specified via --test-size, an instance of that size is to be started on the local host with flux-start as the parent.
A failure of the initial program (such as non-zero exit code) causes flux-start to exit with a non-zero exit code.
- -o, --broker-opts=option_string
- Add options to the message broker daemon, separated by commas.
- -v, --verbose=[LEVEL]
- This option may be specified multiple times, or with a value, to set a verbosity level. See VERBOSITY LEVELS below.
- -X, --noexec
- Don't execute anything. This option is most useful with -v.
- Run brokers with Caliper profiling enabled, using a Caliper configuration profile named PROFILE. Requires a version of Flux built with --enable-caliper. Unless CALI_LOG_VERBOSITY is already set in the environment, it will default to 0 for all brokers.
- (only with --test-size) Set the directory that will be used as the rundir directory for the instance. If the directory does not exist then it will be created during instance startup. If a DIR is not set with this option, a unique temporary directory will be created. Unless DIR was pre-existing, it will be removed when the instance is destroyed.
- Wrap broker execution in a comma-separated list of arguments. This is useful for running flux-broker directly under debuggers or valgrind.
- -s, --test-size=N
- Launch an instance of size N on the local host.
- Set FLUX_FAKE_HOSTNAME in the environment of each broker so that the broker can bootstrap from a config file instead of PMI. HOSTLIST is assumed to be in rank order. The broker will use the fake hostname to find its entry in the configured bootstrap host array.
- After a broker exits, kill the other brokers after a timeout (default 20s).
- Set the mode for the exit timeout. If set to
leader, the exit timeout is only triggered upon exit of the leader broker, and the flux-start exit code is that of the leader broker. If set to
any, the exit timeout is triggered upon exit of any broker, and the flux-start exit code is the highest exit code of all brokers. Default:
- Set the start mode. If set to
all, all brokers are started immediately. If set to
leader, only the leader is started. Hint: in
--setattr=broker.quorum=0to let the initial program start before the other brokers are online. Default:
- Set the directory to be used as the broker rundir instead of creating a
temporary one. The directory must exist, and is not cleaned up unless
--test-rundir-cleanupis also specified.
- Recursively remove the directory specified with
--test-rundirupon completion of flux-start.
- Set the pmi clique mode, which determines how
PMI_process_mappingis set in the PMI server used to bootstrap the brokers. If
none, the mapping is not created. If
single, all brokers are placed in one clique. Default:
- level 1 and above
- Display commands before executing them.
- level 2 and above
- Trace PMI server requests (test mode only).
Launch an 8-way local Flux instance with an interactive shell as the initial program and all logs output to stderr:
flux start -s8 -o,--setattr=log-stderr-level=7
Launch an 8-way Flux instance within a slurm job, with an interactive shell as the initial program:
srun --pty -N8 flux start