flushing private cache flushe entire website cache

[rameshramachandran84-zz]

Hi ,

We noticed an issue related to flushing private block cache flushing entire website cache .

We have configured Flush Event action for controller_action_predispatch which is fired on EVERY request. Every time page is dispatched. See Below.



private
<registry_keys>
<current_category/>
</registry_keys>
<flush_events>
<wishlist_item_save_after/>
<wishlist_item_delete_after/>
<sales_quote_save_after/>
<controller_action_predispatch/>
</flush_events>



We have similar configuration for Footer Block.
Note that Header and Footer blocks are part of EVERY page in Magento.

look at the code that actually initiates FLUSH Event. This code is from turpentine extension.
public function banClientEsiCache( $eventObject ) {
$eventName = $eventObject->getEvent()->getName();
if( Mage::helper( 'turpentine/esi' )->getEsiEnabled() &&
!in_array( $eventName, $this->_esiClearFlag ) ) {
$sessionId = Mage::app()->getRequest()->getCookie( 'frontend' );
if( $sessionId ) {
$result = $this->_getVarnishAdmin()->flushExpression(
'obj.http.X-Varnish-Session', '==', $sessionId,
'&&', 'obj.http.X-Turpentine-Flush-Events', '~',
$eventName );
Mage::dispatchEvent( 'turpentine_ban_client_esi_cache', $result );
if( $this->_checkResult( $result ) ) {
Mage::helper( 'turpentine/debug' )
->logDebug( 'Cleared ESI cache for client (%s) on event: %s',
$sessionId, $eventName );
} else {
Mage::helper( 'turpentine/debug' )
->logWarn(
'Failed to clear Varnish ESI cache for client: %s',
$sessionId );
}
}
$this->_esiClearFlag[] = $eventName;
}
}

we can see that turpentine BANS the block by $sessionId which is actually the Frontend Cookie. (Magento assigned cookie for user session)
As a result, even if we want to flush Header and Footer, its actually flushing all pages tagged with "Frontend" cookie.

Please let us know your thoughts .

[rameshramachandran84-zz]

@miguelbalparda : please share your thoughts

[rameshramachandran84-zz]

@eth8505 : please check

[rameshramachandran84-zz]

Hi, We identified the root cause. the flush events associated with each block is not only flushing the block cache, it is flushing the entire website cache and this is causing issues . As per the Doc its mentioned that cache will only flush for the particular blocks not for the entire pages.

[miguelbalparda]

Would you mind doing a PR with your findings?

[rameshramachandran84-zz]

@miguelbalparda : Can you please get me some idea about the BAN functionality . Is the BAN will flush entire page cache or its only flush particular block cache?

[rameshramachandran84-zz]

@miguelbalparda @aricwatson:

<registry_keys>
<current_category/>
</registry_keys>
<flush_events>
<wishlist_item_save_after/>
<wishlist_item_delete_after/>
<sales_quote_save_after/>
<controller_action_predispatch/>
</flush_events>

the above code added for the header block . So how can we confirm the ban request will only clear the header block cache not the full page cache . Is there any to make sure this . Please let me know .