Sorry, that last paragraph should have read: -- The thing that brought this to my attention was that storePercentUsage was hitting 100% for a multi-GB max store size. I suspect this is due to some crusty data in the indexes themselves - after 5993 x 8mb journals, perhaps a 79mb *index* is not unreasonable. When the *indexes* are deleted and rebuilt, they go down to 2mb. --
Jakub On Tue, Jun 27, 2017 at 10:20 AM, Jakub Korab <jakub.korab.li...@gmail.com> wrote: > Hi all, > > I am seeing some odd behaviour in a 5.14.5 ActiveMQ instance that used > mKahaDB - I have not seen this sort of thing before, and was wondering if > anyone could shed some light on it. > > The directory listing below is for one fragment of an mKahaDB > installation. It is configured for 8mb journal files, and accepts messages > for a single queue only. Messages are 60-80kb in size. > > What I am seeing is a very large index (db.data), often far in excess of > the total size of the journals. The following is not uncommon to what is > happening in other mKahaDB fragments: > > -rw-r--r-- 1 activemq activemq 8388608 Jun 19 18:07 db-5985.log > -rw-r--r-- 1 activemq activemq 8388608 Jun 19 18:09 db-5986.log > -rw-r--r-- 1 activemq activemq 8388608 Jun 19 18:11 db-5987.log > -rw-r--r-- 1 activemq activemq 8388608 Jun 19 18:14 db-5988.log > -rw-r--r-- 1 activemq activemq 8388608 Jun 19 18:16 db-5989.log > > > > > *-rw-r--r-- 1 activemq activemq 99401 Jun 20 00:13 > db-5991.log-rw-r--r-- 1 activemq activemq 8388608 Jun 20 01:00 > db-5990.log-rw-r--r-- 1 activemq activemq 728 Jun 20 01:03 > db-5993.log-rw-r--r-- 1 activemq activemq 8388608 Jun 20 09:32 > db-5992.log*-rw-r--r-- > 1 activemq activemq 3291400 Jun 20 17:54 db.redo > *-rw-r--r-- 1 activemq activemq 79540224 Jun 20 17:54 db.data* > -rw-r--r-- 1 activemq activemq 8388608 Jun 20 17:54 db-5994.log > > Points of note: > - Total journal size is 67.2mb, indexes are 79.5mb. > - db-5990.log is written after db-5991.log, db-5992.log after db-5993.log > (non-sequential writes) > > The thing that brought this to my attention was that storePercentUsage was > hitting 100% for a multi-GB max store size. I suspect this is due to some > crusty data in the indexes themselves - after 5993 x 8mb journals, perhaps > a 79mb journal is not unreasonable. When the journals are deleted and > rebuilt, they go down to 2mb. > > Any ideas as to why the index is so large, and what might cause journals > to be written out of order? > > Thanks, > > Jakub >
