Network Semaphore

The overview and design of the network semaphore service is documented in the design guide.

Configuration Options

The [service_network_semaphore] configuration section contains the settings for the network semaphore service.

[service_network_semaphore]
module = saq.network_semaphore
class = NetworkSemaphoreServer
description = Network Semaphore - global network service for controlling concurrent access to limited resources
enabled = yes

; the address of the network semaphore server (used to bind and listen)
bind_address = 127.0.0.1
bind_port = 53559

; the address of the network semaphore server to the clients that want to use them
; could be the same as the bind_adress and bind_port above
remote_address = 127.0.0.1
remote_port = 53559

; comma separated list of source IP addresses that are allowed to connect
allowed_ipv4 = 127.0.0.1
; directory that contains metrics and current status of semaphores
stats_dir = var/network_semaphore

The service can be found to a specific interface and port as defined by the bind_address and bind_port options. A value of 0.0.0.0 for the bind_address option binds the service to all available network interfaces.

ACE uses the remote_address and remote_port options when requesting network semaphore locks. Note that these settings are valid even if the enabled boolean option is set to False.

You must define precisely what source addresses are allowed to connect to the service using the comma separated list of IP addresses in the allowed_ipv4 option.

stats_dir defines a directory (relative to ../design/data_dir.md) that contains various statistical information regarding the usage of the semaphores.

Logging and Monitoring

The standard logging configuration options apply.

You can view the current status of all defined semaphores by reading the semaphore.status file in the directory defined by the stats_dir configuration setting.