flux-broker-attributes(7)

DESCRIPTION

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:

SESSION ATTRIBUTES

rank
The rank of the local broker.
size
The number of broker ranks in the flux instance
rundir
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.
content.backing-path
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.

TOPOLOGY ATTRIBUTES

tbon.fanout
Branching factor of the tree based overlay network.
tbon.descendants
Number of descendants "below" this node of the tree based overlay network, not including this node.
tbon.level
The level of this node in the tree based overlay network. Root is level 0.
tbon.maxlevel
The maximum level number in the tree based overlay network. Maxlevel is 0 for a size=1 instance.
tbon.endpoint
The endpoint for the tree based overlay network to communicate over.
tbon.zmqdebug
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.
tbon.prefertcp
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.

SOCKET ATTRIBUTES

tbon.parent-endpoint
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.
local-uri
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".
parent-uri
The Flux URI that should be passed to flux_open(1) to establish a connection to the enclosing instance.

LOGGING ATTRIBUTES

log-ring-used
The number of log entries currently stored in the ring buffer.
log-ring-size
The maximum number of log entries that can be stored in the ring buffer.
log-count
The number of log entries ever stored in the ring buffer.
log-forward-level
Log entries at syslog(3) level at or below this value are forwarded to rank zero for permanent capture.
log-critical-level
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.
log-filename
(rank zero only) If set, session log entries, as filtered by log-forward-level, are directed to this file.
log-stderr-mode
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-stderr-level
Log entries at syslog(3) level at or below this value to stderr, subject to log-stderr-mode.
log-level
Log entries at syslog(3) level at or below this value are stored in the ring buffer.

CONTENT ATTRIBUTES

content.acct-dirty
The number of dirty cache entries on this rank.
content.acct-entries
The total number of cache entries on this rank.
content.acct-size
The estimated total size in bytes consumed by cache entries on this rank, excluding overhead.
content.acct-valid
The number of valid cache entries on this rank.
content.backing-module
The selected backing store module, if any. This attribute is only set on rank 0 where the content backing store is active.
content.blob-size-limit
The maximum size of a blob, the basic unit of content storage.
content.flush-batch-count
The current number of outstanding store requests, either to the backing store (rank 0) or upstream (rank > 0).
content.flush-batch-limit
The maximum number of outstanding store requests that will be initiated when handling a flush or backing store load operation.
content.hash
The selected hash algorithm, default sha1.
content.purge-old-entry
When the cache size footprint needs to be reduced, only consider purging entries that are older than this number of seconds.
content.purge-target-size
If possible, the cache size purged periodically so that the total size of the cache stays at or below this value.

WIREUP ATTRIBUTES

hello.timeout
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.
hello.hwm
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.

CONFIG ATTRIBUTES

config.hostlist
The rank-ordered hosts specified in the bootstrap section of the Flux configuration. Hosts are listed in RFC29 hostlist format.

SEE ALSO

flux-getattr(1), flux_attr_get(3)