Implementation > Monitoring services > Monitoring services for Gateway exchanges > Configuration tasks > Buffer management in Gateway

File-transfer monitoring: Buffer management

About buffering of monitoring data

Buffer sizing

Gateway behavior and congestion strategy

About buffering of monitoring data

Gateway uses native processes to deliver monitoring information to the Sentinel monitoring system. To ensure that no monitoring data is lost, Gateway buffers all monitoring data to a buffer file before sending it to Sentinel. This buffer file is named tracker.pmq, and is located in the directory <Gateway install directory>\run_time\data\

Buffer sizing

By default, tracker.pmq can store the monitoring data for 1500 to 3000 file transfers. To increase the capacity of tracker.pmq, you use the pmqctl utility.

You calculate the required size of tracker.pmq file based on the file transfer rate and the average time that Sentinel is unavailable.

For example, consider the case where:

Required tracker.pmq size for one transfer = 8000000/1500 bytes

Total tracker.pmq size required for one transfer * transfers per hour * number of hours

= (8000000/1500)*1000*8 = approximately 43000000 bytes

To modify the default size of the file use the pmqctl command:

pmqctl enlarge $p_home_dir/run_time/data/tracker.pmq 43000000

Gateway behavior and buffer congestion strategy

Gateway operates normally as long as the buffer file tracker.pmq remains less than 50 % full. If tracker.pmq becomes 50 % full, Gateway may suspend activities or refuse data. This situation may also lead to Gateway Navigator being denied access to Gateway.

Gateway provides a configuration parameter, called sentinel_congestion_strategy, to enable you to tune the behavior of Gateway when the file buffering to the Sentinel monitoring system increases dramatically.

To set the congestion strategy use the command peluconf [standalone] set –s sentinel

For example the command peluconf set –s sentinel congestion_strateqy 1 sets the configuration strategy to the level described in the following table.

Congestion strategy values and Gateway behavior:

congestion_strategy value Gateway behavior
0
  • Fill-up ratio >= 50 %
  • Gateway stops scheduling new transfers. New file transfers in requester mode are not initiated until the ratio descends below 50 %.
  • Fill-up ratio >= 60 %
  • Gateway refuses incoming connections. New connections in responder mode are refused until the fill-up ratio descends below 60 %. Transfers on established connections continue to be accepted.
  • Fill-up ratio >= 70 %
  • Gateway refuses incoming requests of transfers. New transfers requested by remote sites are refused. Transfers in progress continue
  • Fill-up ratio >= 80 %
  • Gateway refuses login from applications. Attempts to log to the product are refused with a BUSY status. All user commands including GUIs and applications using the API are impacted. Applications and GUIs that are currently logged to Gateway proceed normally.
1 Similar to strategy 0, except that the fill-up ratio of 80 % is not applied. Applications that interface with Gateway proceed normally regardless of the actual fill-up ratio of the tracker.pmq
2 Gateway does not check the fill-up ratio of tracker.pmq. If tracker.pmq becomes full, new monitoring information is lost. This error condition is detected by Gateway and written to the tracker.pmq file.