The CI jobs would rsync some cached materials to a central instance integration-castor03.integration.eqiad.wmflabs. Typically the local maven cache, npm/composer install caches. That is to speed up the build/save bandwith.
T188375: castor rsync's taking 3-5 minutes for mwgate-npm jobs is about speeding it up, a change has been made to have rsync to no more compress the data to save on CPU usage. When several jobs fetch caches, the CPU was busy and saving compressing save CPU cycles. However that means the amount of data to transfer is way larger.
The Grafana view shows the same network cap at roughly 20 MBps.
The purpose of this task is to find out whether #WMCS does any rate limiting of instances and whether it is possible to raise the cap a bit if at all possible.
The instance hosting the cache is integration-castor03.integration.eqiad.wmflabs (172.16.5.161). It is running on the server cloudvirt1002.
Note the central caching system has reached its limitation and is now a bottleneck, would thus have to replace it with something new and more distributed. But that is an entire topic
Run tc-setup on the instance
Verify by checking integration.integration-castor03.network.eth0.tx_bit: https://graphite-labs.wikimedia.org/render/?width=1280&height=720&target=integration.integration-castor03.network.eth0.tx_bit