Logical log buffer
Version: IDS 7.30 UC7
Question: We have 3 logical log buffers, 32K each. And databases use buffered
logical log (>/dev/null), altogether 8 logical logs. One day users complained
they can't do anything and when we ran onstat -u, we found out something like
this:
.....
e940e864 G--P--- 159686 user1 - e951ceb8 0 0 10 0
eb029efc G-BPX-- 159687 user2 - e951ce60 0 3 9 0
eb02ce04 ------- 159685 eis - 0 0 1 0 0
.....
The first flag was "G" for some sessions, except user eis was still running
(creating temp tables and indexes). But it seemed that all the seesions were
hanging up and it remained the same all morning until eis finished. Looks like
data in buffer can hardly be flushed to disks. Why it was like this, can't
informix automatically flush buffered data to disks when buffers are full?
Anyway to prevent this?
Thx.
The engine does flush the buffers to disk when they are full. What this
indicates is that there is a problem with the disk on which the logical log
file resides. You might want to use iostat and/or vmstat to determine why
the physical IO is taking so long.
"SIMON LIU"
<simon.liu@priszm To: ids@iiug.org
.com> cc:
Sent by: Subject: Logical log buffer [1596]
forum.subscriber@
iiug.org
07/25/2003 03:46
PM
Version: IDS 7.30 UC7
Question: We have 3 logical log buffers, 32K each. And databases use
buffered logical log (>/dev/null), altogether 8 logical logs. One day users
complained they can't do anything and when we ran onstat -u, we found out
something like this:
....
e940e864 G--P--- 159686 user1 - e951ceb8 0 0 10 0
eb029efc G-BPX-- 159687 user2 - e951ce60 0 3 9 0
eb02ce04 ------- 159685 eis - 0 0 1 0 0
....
The first flag was "G" for some sessions, except user eis was still running
(creating temp tables and indexes). But it seemed that all the seesions
were hanging up and it remained the same all morning until eis finished.
Looks like data in buffer can hardly be flushed to disks. Why it was like
this, can't informix automatically flush buffered data to disks when
buffers are full? Anyway to prevent this?
Thx.