Software: Apache/2.0.54 (Fedora). PHP/5.0.4 

uname -a: Linux mina-info.me 2.6.17-1.2142_FC4smp #1 SMP Tue Jul 11 22:57:02 EDT 2006 i686 

uid=48(apache) gid=48(apache) groups=48(apache)
context=system_u:system_r:httpd_sys_script_t 

Safe-mode: OFF (not secure)

/usr/share/doc/db4-devel-4.3.27/ref/lock/   drwxr-xr-x
Free 3.44 GB of 27.03 GB (12.71%)
                            Encoder    Tools    Proc.    FTP brute    Sec.    SQL    PHP-code    Update    Feedback    Self remove    Logout    

Viewing file:     config.html (3.13 KB)      -rw-r--r--

Berkeley DB Reference Guide: Locking Subsystem

Configuring locking

The DB_ENV->set_lk_detect method specifies that the deadlock detector should be run whenever a lock is about to block. This option provides for rapid detection of deadlocks at the expense of potentially frequent invocations of the deadlock detector. On a fast processor with a highly contentious application where response time is critical, this is a good choice. An option argument to the DB_ENV->set_lk_detect method indicates which lock requests should be rejected.

In general, when applications are not specifying lock and transaction timeout values, the DB_LOCK_DEFAULT option is probably the correct first choice, and other options should only be selected based on evidence that they improve transaction throughput. If an application has long-running transactions, DB_LOCK_YOUNGEST will guarantee that transactions eventually complete, but it may do so at the expense of a large number of lock request rejections (and therefore, transaction aborts).

The alternative to using the DB_ENV->set_lk_detect method is to explicitly perform deadlock detection using the Berkeley DB DB_ENV->lock_detect method.

The DB_ENV->set_lk_conflicts method allows you to specify your own locking conflicts matrix. This is an advanced configuration option, and is almost never necessary.

Copyright (c) 1996-2004 Sleepycat Software, Inc. - All rights reserved.