Environment Variables

Environment Variables

You'll rarely need to define environment variables. Don't do it unless you really need them.

Berkeley DB databases

These environment variables allows some specific tuning on BerkeleyDB databases environment. Usually, you won't need to define or use these variables, and you shall not do, unless you've previously read and understood how they work. Check Berkeley DB documentation.

Database
- DB_DB_CACHE_SIZE
Environment
- DB_ENV_CACHE_SIZE
- DB_LK_MAX_LOCKS
- DB_LK_MAX_OBJECTS
- DB_LK_MAX_LOCKERS

When the value of these variables are changed, the new environment may be incompatible with the old one. In this case, you shall stop the filter and remove database enviroment files (__db.* and log.*).

Instead of defining these environment variable, you can use the usual DB_CONFIG file. Read more on BerkeleyDB documentation. If you want to experiment with DB_CONFIG, a starting one can be :

set_cachesize 0 100000000 1
set_lk_max_locks   32768
set_lk_max_objects 32768

Content filter

ORDER_CHECKS - this environment variable defines the order at which content checks are done, separated by commas. Defaut value is XFILES,VIRUS,CONTENT.

Greylisting

Cleaning up databases

Cleaning up greylisting databases (expire, validate, …) is done by a background task which runs, at least, each 10 minutes, as defined by GREY_CLEANUP_INTERVAL configuration option. When this task runs, greylisting databases are locked. On really busy servers, it may be useful to tune these two parameters :

GREY_CLEANUP_SUB_INTERVAL - default value : 120 : 2 minutes
GREY_CLEANUP_DT_LOCK_MAX - default value : 1000 : 1 sec
GREYD_RECV_TIMEOUT - default value : '2000 : 2 secs''

Table of Contents

Environment Variables

Berkeley DB databases

Content filter

Greylisting

Cleaning up databases