Squid_ The Definitive Guide - Duane Wessels [205]
Syntax
min_dns_poll_cnt number
Default
min_dns_poll_cnt 8
Example
min_dns_poll_cnt 10
Related
incoming_dns_average
Name
min_http_poll_cnt
Synopsis
This directive is similar to min_icp_poll_cnt, except that it applies to the TCP socket with which Squid accepts new client requests. Unless you have a thorough understanding of the polling algorithms in the source code, I strongly recommend that you leave this directive set to its default value.
Syntax
min_http_poll_cnt number
Default
min_http_poll_cnt 8
Example
min_http_poll_cnt 12
Related
incoming_http_average
Name
max_open_disk_fds
Synopsis
This directive defines an upper limit on the number of file descriptors that Squid should open for reading and writing cache files on disk. It is relevant for only the ufs and aufs storage schemes. It is a relatively simple hack for measuring the level of Squid's disk activity. Experience shows that performance degrades significantly when Squid hits a filesystem bottleneck.
If Squid reaches this limit, it doesn't attempt to store subsequent cachable responses. Each time that happens, Squid increments the no.too_many_open_files counter (see Section 14.2.1.40). Note that hitting this limit has a negative impact on your hit ratio. You can monitor the number of open disk files by requesting the info page from the cache manager (see Section 14.2.1.24).
If you set this directive to 0, Squid doesn't place any limits on the number of open disk file descriptors.
Syntax
max_open_disk_fds N
Default
max_open_disk_fds 0
Example
max_open_disk_fds 100
Name
offline_mode
Synopsis
When you enable offline_mode, Squid returns every cached response as an unvalidated cache hit. These are tagged with TCP_OFFLINE_HIT in access.log. When in this mode, Squid still attempts to forward cache misses. If your system truly is offline, some requests may hang while waiting for the DNS or HTTP transaction to timeout.
Syntax
offline_mode on|off
Default
offline_mode off
Example
offline_mode on
Name
uri_whitespace
Synopsis
This directive tells Squid what to do about URIs that contain whitespace characters (i.e., space and tab). The default action is to strip out the whitespace and shift the valid characters down as necessary. This is the behavior recommended by RFC 2396.
If you set this directive to allow, Squid doesn't change the URI. It is passed through to the origin server as is. This setting may cause some problems with redirectors and log file parsers. Both use whitespace as a field delimiter, and a URI with whitespace adds an additional field (or fields) to the redirector input line and the access.log entry.
The deny setting instructs Squid to deny such a request, as though it were blocked by the access control rules. Note, however, that the URI is still written to access.log with the whitespace characters.
With the encode setting, Squid changes whitespace characters into their RFC 1738 equivalents. When some origin servers generate URIs that contain whitespace, this is what they should be doing in the first place.
Finally, the chop setting instructs Squid to simply cut off the URI at the first whitespace character.
Syntax
uri_whitespace allow|deny|strip|encode|chop
Default
uri_whitespace strip
Example
uri_whitespace deny
Related
access_log, redirector_program
Name
broken_posts
Synopsis
Certain buggy HTTP servers expect two extra bytes, CR and LF characters, following an HTTP POST message body. It seems unlikely that such uncompliant servers are still in use today. Nonetheless, this access rule list exists to accommodate them. When a request matches a broken_posts rule, Squid appends the extra CRLF characters.
Syntax
broken_posts allow|deny [!]ACLname ...
Default
No default
Example
acl NeedsExtraCRLF dstdomain broken.server.com
broken_posts allow NeedsExtraCRLF
Related
http_access,