Flux broker attributes are parameters that affect how different broker systems behave. Attributes can be listed and manipulated with flux-getattr(1), flux-setattr(1), and flux-lsattr(1).
The broker currently exports the following attributes:
- The rank of the local broker.
- The number of broker ranks in the flux instance
- A temporary directory available for scratch storage within the session. By default, a temporary directory is created for each broker rank, but if rundir is set on the command line, this directory may be shared by all broker ranks running on the same node. If rundir is created by the broker, it is removed during session exit.
- The path to the content backing store file(s). If this is set on the broker command line, the backing store uses this path instead of a temporary one, and content is preserved on instance exit. If file exists, its content is imported into the instance. If it doesn't exist, it is created.
- Branching factor of the tree based overlay network.
- Number of descendants "below" this node of the tree based overlay network, not including this node.
- The level of this node in the tree based overlay network. Root is level 0.
- The maximum level number in the tree based overlay network. Maxlevel is 0 for a size=1 instance.
- The endpoint for the tree based overlay network to communicate over.
- If set to an non-zero integer value, 0MQ socket event logging is enabled, if available. This is potentially useful for debugging overlay connectivity problems. The attribute may not be changed during runtime.
- If set to an integer value other than zero, and the broker is bootstrapping with PMI, tcp:// endpoints will be used instead of ipc://, even if all brokers are on a single node.
- The URI of the ZeroMQ endpoint this rank is connected to in the tree based overlay network. This attribute will not be set on rank zero.
- The Flux URI that should be passed to flux_open(1) to establish a connection to the local broker rank. By default, local-uri is created as "local://<broker.rank>/local".
- The Flux URI that should be passed to flux_open(1) to establish a connection to the enclosing instance.
- The number of log entries currently stored in the ring buffer.
- The maximum number of log entries that can be stored in the ring buffer.
- The number of log entries ever stored in the ring buffer.
- Log entries at syslog(3) level at or below this value are forwarded to rank zero for permanent capture.
- Log entries at syslog(3) level at or below this value are copied to stderr on the logging rank, for capture by the enclosing instance.
- (rank zero only) If set, session log entries, as filtered by log-forward-level, are directed to this file.
- If set to "leader" (default), broker rank 0 emits forwarded logs from other ranks to stderr, subject to the constraints of log-forward-level and log-stderr-level. If set to "local", each broker emits its own logs to stderr, subject to the constraints of log-stderr-level.
- Log entries at syslog(3) level at or below this value to stderr, subject to log-stderr-mode.
- Log entries at syslog(3) level at or below this value are stored in the ring buffer.
- The number of dirty cache entries on this rank.
- The total number of cache entries on this rank.
- The estimated total size in bytes consumed by cache entries on this rank, excluding overhead.
- The number of valid cache entries on this rank.
- The selected backing store module, if any. This attribute is only set on rank 0 where the content backing store is active.
- The maximum size of a blob, the basic unit of content storage.
- The current number of outstanding store requests, either to the backing store (rank 0) or upstream (rank > 0).
- The maximum number of outstanding store requests that will be initiated when handling a flush or backing store load operation.
- The selected hash algorithm, default sha1.
- When the cache size footprint needs to be reduced, only consider purging entries that are older than this number of seconds.
- If possible, the cache size purged periodically so that the total size of the cache stays at or below this value.
- The reduction timeout (in seconds) for the broker wireup protocol. Before the timeout, a topology-based high water mark is applied at each node of the tree based overlay network. After the timeout, new wireup information is forwarded upstream without delay. Set to 0 to disable the timeout.
- The reduction high water mark for the broker wireup protocol, normally calculated based on the topology. Set to 0 to disable the high water mark.
- The rank-ordered hosts specified in the
bootstrapsection of the Flux configuration. Hosts are listed in RFC29 hostlist format.