How to adjust the synchronization speed in Red Hat Satellite 6.10 or later?

Environment

• Red Hat Satellite 6.10 and newer.
• Pulp3.

Issue

• How to adjust the synchronization speed in Red Hat Satellite 6.10 or later?

• Content sync from Satellite to remote Capsule(s) uses up all the available bandwidth. While syncing content to remote Capsule(s), the WAN connection is almost completely occupied by the Capsule sync traffic, causing other services to suffer.

Resolution

• Red Hat Satellite 6.9 and earlier releases had the support of Pulp2 and the –-katello-pulp-max-speed option was applicable there. This option is no longer available on Red Hat Satellite 6.10 and later releases as they are based on Pulp3.

  • Because the -–katello-pulp-max-speed option operated on the level of individual sync tasks, it was not suitable on its own to be used as a mechanism for limiting the bandwidth of a Satellite installation.

• A better and more accurate solution is to use an appropriate network traffic shaping policy. Tools such as Traffic Control (the tc command) can be used to set global, system-wide limits on the utilization of network interface resources.

  • Configuring bandwidth limitations using Traffic Control (the tc command) ensures that no matter what activities are taking place on the machine, they will not violate the administrator’s intent.

  • The easiest and most straight-forward approach is to apply the network traffic shaping policy on the Satellite server. However, in some cases, it might also be necessary to apply it on individual Capsules.

  • Please refer to the following knowledgebase resources for more detailed information on network traffic shaping using Traffic Control (the tc command):

    - [How do I configure a network interface bandwidth limitation?](https://access.redhat.com/solutions/40824)
    
    - [How to limit the bandwidth of incoming packets](https://access.redhat.com/solutions/1324033)
    
    - [How to apply a bandwidth or latency limitation to network interface or protocol?](https://access.redhat.com/solutions/69133)
    

For more knowledgebase articles/solutions related to Red Hat Satellite 6.x Pulp 3.0 Issues, please refer to the Consolidated Troubleshooting Article for Red Hat Satellite 6.x Pulp 3.0-related Issues

Root Cause

• Satellite and Capsules have many workers, threads and services handling network traffic of various sorts: from clients to Capsule, Capsule to Satellite, Satellite to Capsule etc.

• Attempting to put bandwidth limitations on a Capsule within the Satellite code base is fraught with edge cases, inconsistencies and will lead to a worse experience.

• Pulp2 had the –-katello-pulp-max-speed option in Red Hat Satellite 6.9 and earlier, and it suffered from all of these problems.

• Satellite, even if it had complete network awareness between all of its own services, has no awareness of what any other services on the machine or machines on the network might be doing. The only actor on the machine with that kind of global knowledge and control over networking is the operating system itself.

• Customers who desire to put bandwidth limitations on a Capsule need to do so from a central point (i.e., on Satellite server).

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