请教一个openldap的我问题,服务器突然断电,数据丢失的问题!

jtome

我用的是 openldap 2.16  在linux as 3 上运行,当服务器突然断电后,我往ldap上录入的数据全部丢失,有时可能是前几天的数据,一直没找出原因,请大家帮忙分析一下!

jtome

自己在顶一下

gary_tay88

Please run "db_recover".

I assume you are using "bdb" database.

jtome

我查了一下.db_recover :
        ldap要停掉,然后db_recover ,在启动ldap ,我是想能不能每次入库的ldap数据立即同步到ldap数据库中.而不是在内存中,当突然停电后,数据就会丢失(我用的是 bdb 4.1.25),请大家帮忙解决一下!

gary_tay88

Pls upgrade to BDB 4.2.52 + 2 patches.

# cd /var/tmp
# wget http://www.sleepycat.com/update/snapshot/db-4.2.52.tar.gz
# wget http://www.sleepycat.com/update/4.2.52/patch.4.2.52.1
# wget http://www.sleepycat.com/update/4.2.52/patch.4.2.52.2
# gzip –d db-4.2.52.tar.gz
# tar xvf db-4.2.52.tar
# chmod u+w db-4.2.52/mp/mp_fget.c
# chmod u+w db-4.2.52/lock/lock.c
# cd db-4.2.52
# patch -i ../patch.4.2.52.1
# patch -i ../patch.4.2.52.2

OpenLDAP upcoming version 2.3 is said to have auto-detection and update of DB checkpoint changes.

OR you may download Symas's CDS from http://www.symas.com, which is OpenLDAP 2.2.X modified with this auto features.

See:
http://www.openldap.org/lists/openldap-software/200501/msg00303.html

Gary

gary_tay88

Please read this related info:

http://www.openldap.org/faq/data/cache/1162.html

===

If you put "checkpoint 1024 5" in slapd.conf (to checkpoint after 1024kb or 5 minutes, for example), this does not checkpoint every 5 minutes as you may think. The explanation from Howard is:
``In OpenLDAP 2.1 and 2.2 the checkpoint directive acts as follows - *when there is a write operation*, and more than <check>; minutes have occurred since the last checkpoint, perform the checkpoint. If more than <check>; minutes pass after a write without any other write operations occurring, no checkpoint is performed, so it's possible to lose the last write that occurred.''

In other words, a write operation occurring less than "check" minutes after the last checkpoint will not be checkpointed until the next write occurs after "check" minutes have passed since the checkpoint.

This has been modified in 2.3 to indeed checkpoint every so often; in the meantime a workaround is to invoke "db_checkpoint" from a cron script every so often, say 5 minutes.

===

Gary

liuxuefeng

在openldap的 slapd.conf中有一个参数，是来控制数据同步的，也就是决定什么时候把内存的中的数据 保存到硬盘中  我猜测你的这个参数没有配置 dbnosync