Hello Allan, I was hacking a bash script to help explain the issue [1] but I realized it was not related to the volume getting full. Actually the "problem" was that the Index was getting full. On the first test scenario that happened almost when the storage got full, but on the scenario built by the script, that happens with about 41% of storage usage. On [2] I explain what the script does, and why I think the problem was the index. But it's actually not an issue, it's just that some objects have to be evicted so others can be saved. Why the RAM is so little used on this situation is still not very clear, but I suppose it's probably due to the high hash collision rate that the situation generates.
Thanks for the help! [1] https://drive.google.com/file/d/0B_pQbXm7hKZ4R0ZfOU5sS0Y5NGc/view?usp=sharing [2] https://drive.google.com/file/d/0B_pQbXm7hKZ4RmV0WHdoMWNtUjA/view?usp=sharing Acácio Centeno Software Engineering Azion Technologies Porto Alegre, Brasil +55 51 3012 3005 | +55 51 8118 9947 Miami, USA +1 305 704 8816 Quaisquer informações contidas neste e-mail e anexos podem ser confidenciais e privilegiadas, protegidas por sigilo legal. Qualquer forma de utilização deste documento depende de autorização do emissor, sujeito as penalidades cabíveis. Any information in this e-mail and attachments may be confidential and privileged, protected by legal confidentiality. The use of this document require authorization by the issuer, subject to penalties. 2015-02-05 12:59 GMT-02:00 Alan M. Carroll <a...@apache.org>: > Tuesday, February 3, 2015, 2:45:03 PM, you wrote: > > > Hello, > > > We've being performing some cache tests and noticed two issues that we > > would like to check with the community: > > > 1. The interim cache is limited to the same size as the RAM cache, no > > matter how big the partition allocated to it is. > > Unfortunately the developers of the interim cache don't really work on > Traffic Server anymore and I'm not sure anyone left understands how it > works. > > > 2. Whenever a volume gets full and the write head begins writing to the > > volume's start again, the RAM cache gets unused for a while, and requests > > that could be served from RAM get served from the storage. > > That seems very odd. There shouldn't be any interaction between stripe > wraps and use of the ram cache, especially since the ram cache is filled > from reads which should be happening from all parts of the stripe. When you > say it is unused, is this for objects just written, or do no objects seem > to end up in the ram cache? > >
