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Re: 1.8 Gb OpenLdap DB.....



--On Wednesday, November 26, 2003 5:32 AM -0500 james liang <blueyonder@excite.com> wrote:


The system I am building can tolerate losing some recently modified data
when the server shutdown.  However, I really care about having openldap
run forever with no database corruptions.  In this case, will "set_flags
DB_TXN_NOSYNC" help with the stability of the whole system?


No.

From <http://www.sleepycat.com/docs/api_c/env_set_flags.html>

DB_TXN_NOSYNC
If set, Berkeley DB will not write or synchronously flush the log on transaction commit. This means that transactions exhibit the ACI (atomicity, consistency, and isolation) properties, but not D (durability); that is, database integrity will be maintained, but if the application or system fails, it is possible some number of the most recently committed transactions may be undone during recovery. The number of transactions at risk is governed by how many log updates can fit into the log buffer, how often the operating system flushes dirty buffers to disk, and how often the log is checkpointed.



So, if your system hits issues while running with that flag set, you may lose even more data than you would otherwise.

--Quanah

--
Quanah Gibson-Mount
Principal Software Developer
ITSS/TSS/Computing Systems
ITSS/TSS/Infrastructure Operations
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html