Details
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Question/Request
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Resolution: Unresolved
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Major
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9223372036854775807
Description
In LU-6943 the osc_read and osc_write are removed.
This information was very important to understand how an application was using the local cache versus sending data over the network.
This is was an example:
snapshot_time 1454067781.979713 secs.usecs read_bytes 100000 samples [bytes] 4096 4096 409600000 write_bytes 100000 samples [bytes] 4096 4096 409600000 osc_read 401 samples [bytes] 4096 1048576 409600000 osc_write 391 samples [bytes] 655360 1048576 409600000 open 3 samples [regs] close 3 samples [regs] seek 2 samples [regs] truncate 1 samples [regs] getxattr 100000 samples [regs] inode_permission 7 samples [regs]
After the LU-6943, I'm assuming those informations are available on each stats under each osc: osc.*.stats
osc.zlfs2-OST001f-osc-ffff8820254c4000.stats= snapshot_time 1477130565.324299 secs.usecs req_waittime 1584 samples [usec] 170 7238 2291201 3700860537 req_active 1584 samples [reqs] 1 2 1618 1686 read_bytes 432 samples [bytes] 983 1048576 306500567 291188566310545 write_bytes 1148 samples [bytes] 983 1048576 1181807521 1239149817647387 ost_read 432 samples [usec] 170 4809 575487 981550847 ost_write 1148 samples [usec] 255 6154 1707192 2666192812 ldlm_cancel 1 samples [usec] 264 264 264 69696 obd_ping 2 samples [usec] 247 773 1020 658538
I'm assuming the old osc_read == SUM(read_bytes in osc.*.stats). Could you please confirm?
Normally the SUM(read_bytes in osc.*.stats) should be = of the read_bytes in llite.*.stats when the application is reading data from the network or < when the application is reading data already in the VFS cache. Shouldn't be possible to have a situation where SUM(read_bytes in osc.*.stats) > read_bytes in llite.*.stats in theory.
I did some experiment and I found that the SUM(read_bytes in osc.*.stats) > read_bytes in llite.*.stats. Could you explain why?