[Mediawiki-l] how to make cached never expire

[Enrique]

I want to make the cache never expire, my mediawiki is for off line
read  . 
What's is 'apiThumbCacheExpiry' max value ? 
i can make thumbs never expire?
$wgHTTPTimeout by default is 3 milliseconds , i had increase this
value , but the response of pages are slow while the thumbs images are
downloading , and sometimes when reached this time the  the page go
blank and no result.
how to make the page show first, and them  images thumb show while  we
are reading the page or article.?

regards 
 

$wgHTTPTimeout = 90000; //milisegundos
$wgHTTPProxy = "http://PyproxySquidIP:SquidPort";

$wgForeignFileRepos[] = array(
   'class'                   => 'ForeignAPIRepo',
   'name'                    => 'shared',
   'hashLevels'              => '2',
   'hasSharedCache'          => $wgCacheSharedUploads,
   'apibase'                 =>
'http://commons.wikimedia.org/w/api.php',
   'fetchDescription'        => false, // Optional
   'descriptionCacheExpiry'  => 432000, // 12*5 hours, optional
   'apiThumbCacheExpiry'     => 864000, // 12 hours, optional, but
required for local thumb caching
);