Squid_ The Definitive Guide - Duane Wessels [207]
Syntax
coredump_dir pathname
Default
No default
Example
coredump_dir /squid/var
Name
ignore_unknown_nameservers
Synopsis
Squid normally checks that DNS replies come from the same IP address to which the query was sent. If the addresses don't match, Squid writes a warning to cache.log and ignores the reply. Some installations use an /etc/resolv.conf trick to query any local name server. If the name server IP address is 0.0.0.0, DNS queries are broadcast on the local area network. The replies, however, come from specific addresses. If you want to use this trick, you must disable the ignore_unknown_nameservers directive.
Syntax
ignore_unknown_nameservers on|off
Default
ignore_unknown_nameservers on
Example
ignore_unknown_nameservers off
Related
dns_nameservers
Name
digest_generation
Synopsis
This directive controls whether or not Squid generates a Cache Digest for its own contents. It is enabled by default, when you give the —enable-cache-digests option to ./configure. You may want to disable it if you know that you don't have any neighbors who request your digest.
Syntax
digest_generation on|off
Default
digest_generation on
Example
digest_generation off
Related
cache_peer, digest_bits_per_entry, digest_rebuild_period, digest_rewrite_period, digest_swapout_chunk_size, digest_rebuild_chunk_percentage
Name
digest_bits_per_entry
Synopsis
This directive affects the size of Squid's Cache Digest, based on the estimate for the total number of cache entries. Reducing the size of the digest results in lower memory usage but a higher false hit probability.
Syntax
digest_bits_per_entry number
Default
digest_bits_per_entry 5
Example
digest_bits_per_entry 4
Related
digest_generation, store_avg_object_size, cache_dir
Name
digest_rebuild_period
Synopsis
The digest rebuild period is how often Squid generates the digest of its own cache. This is a fairly CPU-intensive procedure, so you don't want to run it too often. On the other hand, the digest becomes less representative of Squid's contents as more time passes.
Syntax
digest_rebuild_period time-specification
Default
digest_rebuild_period 1 hour
Example
digest_rebuild_period 4 hours
Related
digest_generation, digest_rewrite_period, digest_swapout_chunk_size, digest_rebuild_chunk_percentage
Name
digest_rewrite_period
Synopsis
The digest rewrite period is how often Squid generates an on-disk cached HTTP response for its Cache Digest. This is the response sent to neighbors that request Squid's digest. In most cases digest_rewrite_period should be the same as digest_rebuild_period.
Syntax
digest_rewrite_period time-specification
Default
digest_rewrite_period 1 hour
Example
digest_rewrite_period 4 hours
Related
digest_generation, digest_rebuild_period, digest_swapout_chunk_size, digest_rebuild_chunk_percentage
Name
digest_swapout_chunk_size
Synopsis
This directive controls the amount of data written to disk for each call to the digest swapout function. Squid services normal cache traffic (client requests, server responses, etc.) in between digest swapout calls. If the value is too large, Squid blocks on the disk I/O and delays normal cache traffic.
Syntax
digest_swapout_chunk_size size-specification
Default
digest_swapout_chunk_size 4 KB
Example
digest_swapout_chunk_size 16 KB
Related
digest_generation, digest_rewrite_period, digest_rebuild_chunk_percentage
Name
digest_rebuild_chunk_percentage
Synopsis
This directive specifies the percentage of hash-table buckets Squid scans during each call to the digest rebuild procedure. Squid services normal cache traffic in between these calls. Since this scanning is CPU-intensive, user requests may be delayed for a small, but noticeable amount of time. If you suspect a performance problem during the rebuild phase, decrease the digest_rebuild_chunk_percentage value.
Syntax
digest_rebuild_chunk_percentage percentage
Default
digest_rebuild_chunk_percentage