Skip to content
Store ID helper AKA Dynamic Content Booster is extremely fast, scalable, enterprise-grade, high-performance multi-threaded content deduplicator, written in C++14. It works with any Squid starting with v3 and with all products based on it. Supported templates are listed in the project wiki
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.


Store ID helper AKA Dynamic Content Booster is scalable, enterprise-grade, high-performance multi-threaded content deduplicator. It works with any Squid starting with v3 and with all products based on it.

It uses standard helper protocol to interconnect with cache.

DCB supports up to 4096 threads per helper process.


Libraries compatibility

Usually helper statically linked with runtime libraries.

Note: If it built with dynamic linking, make sure your libstdc++/libc++ is at least 5.2 version. Upgrade if required first.

Squid configuration for production

Unpack archive and run (example):

unzip store-id-helper*.zip your_destination_binary_dir

Copy all acl.* files to your squid config dir (default is /usr/local/squid/etc) and add this to your squid.conf:

--------------- Cut --------------

# No cache directives
acl dont_cache_url url_regex "/usr/local/squid/etc/acl.url.nocache"
cache deny dont_cache_url

# Store rewrite ACLs
acl software_and_updates url_regex "/usr/local/squid/etc/acl.url.updates"
acl store_rewrite_list_web url_regex "/usr/local/squid/etc/acl.url.rewrite_web"
acl store_rewrite_list_web_path urlpath_regex "/usr/local/squid/etc/acl.urlpath.rewrite_web"
acl store_rewrite_list_web_cdn url_regex "/usr/local/squid/etc/acl.url.rewrite_cdn"
acl store_rewrite_list urlpath_regex "/usr/local/squid/etc/acl.urlpath.rewrite_other"

# Storeurl rewriter
store_id_program /usr/local/bin/store-id-helper
# where N should equal helper internal queue size (1024 by default)
store_id_children 4 startup=1 idle=1 concurrency=N
# Store ID access
acl store_id_get_method method GET
store_id_access deny !store_id_get_method
acl url_storeid_deny url_regex "/usr/local/squid/etc/acl.url.storeid_deny"
store_id_access deny url_storeid_deny
store_id_access allow software_and_updates
store_id_access allow store_rewrite_list_web
store_id_access allow store_rewrite_list_web_cdn
store_id_access allow store_rewrite_list_web_path
store_id_access allow store_rewrite_list
store_id_access deny all
store_id_bypass off

range_offset_limit 8192 KB !dont_cache_url all

--------------- Cut --------------

Adjust children value in accordingly to your load spikes (usually this settings is enough). Adjust paths to fit your setup.

Also add this refresh pattern rules on top of your refresh_patterns:

refresh_pattern	squidinternal	43200	100%	518400	override-expire refresh-ims reload-into-ims ignore-private store-stale ignore-no-store

and put all acl.* files into your squid's config directory. After all, just squid -k reconfigure and enjoy!

Vimeo autoplay/chunked caching issue

To prevent Vimeo using chunked videostreams, which leads autoplay problems and bad byte hit for videos, add this acl:

# Vimeo autoplay/chunked HTML5 caching issue
acl vimeo_chunked url_regex vimeo.*master\.json
http_access deny vimeo_chunked

anywhere above your final blocking rule and reconfigure your squid.

STORE-ID command-line options

** -d log debug to /var/log/store-id-helper.log

** -t<optional: time in ms> set debug + timing flag (when built with --enable-timing)

Note: When specified time in ms, will log only queries with timing more than specified value.

** -l set log file. Default is /var/log/store-id-helper.log

Note: You should specify full path + file name. Directory should exists and has permissions to write for proxy non-privileged user. If file does not exists, it will create. If file exists, it will appends.

Note: Default log, when uses, should exists and has permissions to write for proxy non-privileged user.

** -p - set non-default processing threads. Valid range 1..4096.

Note: If non-specified, helper internal concurrency is hardware concurrency by default. Values less than 1 is set to 1, values above 4096 sets to 4096 automatically.

Note: To run in 1-thread mode (for debug purposes or support legacy non-concurrent mode) just specify 0 or 1 thread.

** -q - set non-default thread pool queue size. Valid range 1024..8192.

Note: Queue size should be power of 2. If not - will round to nearest power of 2. Values less 1024 will always set to 1024.

** -a - turns on affinity.

Note: By default, helper builds with threads affinity support (on supported platforms, now Solaris/Linux/FreeBSD). On unsupported platforms this control unavailable and not shown.

Note: Affinity turned off by default. See "Affinity" below.

** -v show helper version and exit

** -h|-? show short help about command-line arguments and exit

Hardware concurrency

To determine real hardware concurrency, just run tools_gethwc utility. Please, don't forget about another processes on server.

Note: Determined value will set as default helper concurrency.


This option will use CPU/core affinity. Thread pool uses round-robin algorithm to bind threads across online CPU/cores. Option useful in some cases/platforms and designed for predictive scheduling and helper latency.


To debug helper, make sure log file exists and squid has permissions to write to first:

# ls -al /var/log/store-id-helper.log
-rw-r--r-- 1 squid squid 809391 Feb  5 17:30 /var/log/store-id-helper.log

Then add -d option to helper in squid.conf:

store_id_program /usr/local/bin/store-id-helper -d

and reconfigure squid.

Now debug logging enabled. Beware, on high-load servers log grows very fast, to keep logging don't forget to configure this log rotation too.

You can use arbitrary log file using -l command-line option (see "STORE-ID command-line options" paragraph above).

Log records structure is:

<-- 130
--> 130 OK store-id=

<Direction of query> [channel ID] <input URL>
<Direction of query> [channel ID] <helper response>

Trial period

Trial period is 30 days. After this, helper will never start.

You can’t perform that action at this time.