DS

Owned by Martin Gudme Søndergaard
Nov 14, 2023
4 min read

Introduction

If a Base Agent has the role of Distribution Server (DS), it will show a DS tab in which configuration, state, and status is shown.

In this section, the current state is shown along with a timestamp of when the state was last changed. In addition, the mode of the Distribution Server is shown (see Distribution Server (BAADS) for configuration) and when the last configuration was received. This is useful when verifying that configuration changes made in the CapaInstaller Console have been applied.

The Management points field shown which Management points are being handled in both client requests and when preloading. '

The 'Max file requesters' is similar to that of an ordinary Base Agent in File share mode except that the Distribution Server is more likely to be utilized by clients. Every single Base Agent can have 2, 5, 20 peering sources for a file and they will spread out the utilization between them but none of them will have more than one Distribution Server, so the pressure on that DS will, at times, be higher. This does not mean that the DS cannot handle more file requests on the same file at the same time. It simply means that the DS will only serve the file to 5 (in this example) clients simultaneously. 

When more clients are requesting the same file, that may or may not yet be present in the DS' file cache, they are each receiving their number in the queue to that file. When the DS has completed the remote transfer from the Front-end Server, clients with a place in the queue higher than 5 will wait (the retry delay) and roll back the discovery process, which will then reassess the situation and start by looking for the file on nearby peers.

The progress timeout is a TimeSpan which the DS uses to monitor the Preload operation of new files from the Front-end Server. If the Progress (of the file copy process) remains stationary for this TimeSpan, the whole preload operation is concluded to be failed and a system notification is sent to the Front-end Server which will then show up in the CapaInstaller Console. Any issued system notification will be auto-resolved upon completing the preload operation later on when the DS is retrying the preload.

Compliance

The compliance status varies between Distribution Servers, depending on the mode that they are in. A Distribution Server in...

  • Fetch mode is always compliant because it will simply fetch requested files on demand.
  • FetchAndPreload mode is compliant once it has completed the first preload because it can always fetch files from the Front-end Server which is not yet locally present. 
  • Preload mode is compliant when the Preload has completed. If it is being requested a file that is not present but actually part of a software package that is linked to the DS but just not preloaded yet, the request is denied, and the DS becomes 'Not compliant'.

Only FetchAndPreload and Preload modes can preload files either by schedule, or an 'Update now' operation on the DS in the System plugin of the CapaInstaller Console or on a Software package in the Configuration Management plugin of the CapaInstaller Console.

While preloading, the compliance shows the progress of the copy operation of new or updated files from the Front-end Server. After completion, the Variable will change into 'Compliant'.

The preload of a Distribution Server in FetchAndPreload or Preload mode can be initiated either by schedule, set in the properties of the DS in the System plugin or by UnitCommand. A UnitCommand is received by the /Select' mechanism and can either unitcommandFull or unitcommandSingle. the unitcommandFull is issued when you right-click a DS in the System plugin and select 'Update Now'. The unitcommandSingle is an 'Update now' operation on a single package in the Configuration Management plugin.

The Status field will show progress while preloading and the result of the last preload when completed.

With a DS in FetchAndPreload or preload mode, an optional schedule can be set. If set, it has an Interval start and can have an interval end and a recurrence. It all sums up to a Pattern like; 'Daily between 01:00 and 05:00'. Along with that both the 'Last preload' and the calculated 'Next preload' is shown.