Writable WNs:

• The change was deployed to the prod farm last week
• Turned out that the gateway memory consumption increase significanlty under heavy io load, causing occasional OOM kills
  • Buffer size was fixed -- from 8 bytes to 8MiB
  • Problems triggered mostly by reads, due to xcache-gateway interraction peculiarities
    • Xcache can use multiple threads to fetch file blocks, and each thread is treated as a separate client, so a separate buffer is created
  • The change was rolled back
  • New version of xrd-ceph where buffering is only applied to write operations is being tested on the LHCb-only WN.