Options

The following options can be specified in the options statement, as described in the previous chapter.

Table 3-15. List of supported global options in syslog-ng

NameAccepted valuesDescription
time_reopen()numberThe time to wait before a died connection is reestablished
time_reap()numberThe time to wait before an idle destination file is closed.
sync()numberThe number of lines buffered before written to file
mark()numberThe number of seconds between two MARK lines. NOTE: not implemented yet.
stats()numberThe number of seconds between two STATS.
log_fifo_size()numberThe number of lines fitting to the output queue
chain_hostnames()yes or noEnable or disable the chained hostname format.
keep_hostname()yes or noEnable or disable hostname rewriting.
check_hostname()yes or no Enable or disable whether the hostname contains valid characters.
bad_hostname()regular expression A regexp which matches hostnames which should not be taken as such.
create_dirs()yes or noEnable or disable directory creation for destination files.
owner()userid.
group()groupid.
perm()permission value.
dir_owner()userid.
dir_group()groupid.
dir_perm()permission value.
use_time_recvd()yes or noUse the time a message is received instead of the one specified in the message.
use_dns()yes or noEnable or disable DNS usage. syslog-ng blocks on DNS queries, so enabling DNS may lead to a Denial of Service attack. To prevent DoS, protect your syslog-ng network endpoint with firewall rules, and make sure that all hosts, which may get to syslog-ng is resolvable.
dns_cache()yes or noEnable or disable DNS cache usage.
dns_cache_size()numberNumber of hostnames in the DNS cache.
dns_cache_expire()numberNumber of seconds while a successful lookup is cached.
dns_cache_expire_failed()numberNumber of seconds while a failed lookup is cached.
log_msg_size()numberMaximum length of message in bytes.
use_fqdn()yes or noAdd Fully Qualified Domain Name instead of short hostname.
gc_idle_threshold()number Sets the threshold value for the garbage collector, when syslog-ng is idle. GC phase starts when the number of allocated objects reach this number. Default: 100.
gc_busy_threshold()number Sets the threshold value for the garbage collector, when syslog-ng is busy. GC phase starts when the number of allocated objects reach this number. Default: 3000.