Dear developers,
Recently I met some troubles when I read the Ceph’s source code and understand the architecture.
The details of problems are as followed.
1.In monitoring tools, they can collect much data when Ceph runs. I wonder what
kind of data the Ceph can provide (object data, PG data or other data?). Could the
Ceph provide every object’s data (e.g. The times the object is read or wrote
,the latest time the object is used ,etc.) ,if Ceph could ,in source code ,where
could I find these details. I really want to know the monitoring data the Ceph
can provides and where they are in source code so that I could know how to use it
more efficiently. For example, I know the Ceph could provide the data of the
objects’ number per PG, the read and write bandwidth, but I couldn’t find how to
achieve these in source code.
2.From official documents, Ceph provides the cache tiering to improve
performance. But I couldn’t find more details to describe the cache tiering
like which kind of algorithm the cache agent uses. In the source code, where
could I find these?
3.In write process , there are two responses to client ,first is from journal and
second is occurred when object writes to real disk .so when I write a object to
Ceph using librbd, does not the write finish until the second response occurs and
what mean the first and second responses for clients? When a object writes to journal
but not to filestore (that is not to disk ), could I read this object? If I could,
where could I read this object?
Really thanks a lot.
Yours sincerely,
Chay ��.n��������+%������w��{.n����z��u���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
