innodb_extra_undoslots option is disabled error

[Vadim Tkachenko]

Percona Server may complain

"innodb_extra_undoslots option is disabled but it was enabled before"

after upgrade from MySQL,
but innodb_extra_undoslots never used.

[Yasufumi Kinoshita (yasufumi-kinoshita)]

It seems to detect uncleared area of builtin InnoDB.
(builtin InnoDB doesn't clear unused area of the page)

OK...

more exact check is needed.
I will try to implement it.

[Yasufumi Kinoshita (yasufumi-kinoshita)]

The first aid for the bug have been pushed

http://bazaar.launchpad.net/~percona-dev/percona-server/release-5.1.52-12/revision/137
http://bazaar.launchpad.net/~percona-dev/percona-server/release-5.1.51-12/revision/135

The first aid is to pass 0 also at least as not used.
The first aid pass if the extended slots area filled with 0, but not pass with other values.

--- innodb_expand_undo_slots.patch 2010-10-04 11:53:08 +0000
+++ innodb_expand_undo_slots.patch 2010-11-12 07:29:47 +0000
@@ -117,7 +117,7 @@
 + page_no = mtr_read_ulint(rseg_header + TRX_RSEG_UNDO_SLOTS
 + + i * TRX_RSEG_SLOT_SIZE,
 + MLOG_4BYTES, &mtr);
-+ if (page_no != FIL_NULL) {
++ if (page_no != 0 && page_no != FIL_NULL) {
 + srv_extra_undoslots = TRUE;
 + fprintf(stderr,
 +"InnoDB: Error: innodb_extra_undoslots option is disabled, but it was enabled before.\n"