[Server-devel] Squid tuning recommendations for OLPC School Server tuning...

[Adrian Chadd]

2008/9/24 Martin Langhoff <martin.langhoff at gmail.com>:

> Good hint, thanks! If we did have such a control, what is the wired
> memory that squid will use for each entry? In an email earlier I
> wrote...

sizeof(StoreEntry) per index entry, basically.


>  - Each index entry takes between 56 bytes and 88 bytes, plus
> additional, unspecificed overhead. Is 1KB per entry a reasonable
> conservative estimate?

1kb per entry is pretty conservative. The per-object overhead includes
the StoreEntry, the couple of structures for the memory/disk
replacement policies, plus the MD5 URL for the index hash, whatever
other stuff hangs off MemObject for in-memory objects.

You'll find that the RAM requirements grow a bit more for things like
in-memory cache objects as the full reply headers stay in memory, and
are copied whenever anyone wants to request it.

>  - Discussions about compressing or hashing the URL in the index are
> recurrent - is the uncompressed URL there? That means up to 4KB per
> index entry?

The uncompressed URL and headers are in memory during:

* request/reply handling
* in-memory object; (objects with MemObject's allocated); on-disk
entries just have the MD5 URL hash per StoreEntry.

HTH,

Oh, and I'll be in the US from October for a few months; I can always
do a side-trip out to see you guys if there's enough interest.


Adrian