The changes as released in the latest HashTable have removed the error 
presented from running horde-clear-cache.

It has also resolved the original issue - changes to permissions are 
applied immediately.

Thanks.

And what I should have said already - thank you Michael, I will give 
the git changes a try and see what they do. :)

?? Huh?
2.4.10, released March 2012, so not very old. Pear redis is up to date.
So, some questions please:

1. A google search for memcache horde clear cache came back with 
nothing that I could see as relevant. Could you please point me in the 
direction of the discussion, or summarise?

2. Can you clarify your statement that I can't "expect to clear the 
cache". I have no issues at all clearing the cache, as I stated 
earlier: "...if I run "redis-cli flushall" after making the 
permissions change it works." That runs without error, and clears the 
redis cache, as I would expect. The issue is that I am having to do 
that manually when I make a change in Horde, rather than Horde doing 
it automatically when I make a change that results in stale cache.

3. If Horde is configured to use redis, does running horde-clear-cache 
call a redis-cli flushall? What redis mechanism is called to clear the 
cache?

4. Does making a change in Horde that is likely to be impacted by 
stale cache (e.g. a permissions change such as that described here) 
automatically attempt to clear the cache? In other words, if redis 
cache was working correctly (i.e. supports keys()), would a change in 
permissions such as I have done in this ticket automatically clear the 
cache, thus not requiring me to "manually purge the backend..."?

If a newer version of redis will result in automatic cache clearing, 
then I will happily upgrade it. If not, then my reasoning behind this 
ticket still stands -

"If it is too complex to automate a cache-clear with permissions 
changes, perhaps an Apply button that does a cache-clear? Or at the 
very least commentary on the permissions page that changes may not 
take effect until cache is cleared."

You are SOL then.  Your version of redis is probably too old.  There 
is no reason keys() should not work (and I can't reproduce).

Regardless, as has been said multiple times before - you can't be 
using memcache-like caching mechanisms and expect to clear the cache.   
This is not how those backends were designed.  If you have a redis 
backend that doesn't support keys(), you will have to manually purge 
the backend yourself through some other mechanism.

Changes have been made in Git (master):

commit f47d1533998d3c270f2d4beb1de266e423a0411f
Author: Michael M Slusarz <slusarz@horde.org>
Date:   Mon Jul 15 14:06:32 2013 -0600

     [mms] Workaround broken redis installations that don't support 
the keys() command (Bug #12416).

  framework/HashTable/lib/Horde/HashTable/Predis.php |   14 ++++++++------
  framework/HashTable/package.xml                    |    4 ++--
  2 files changed, 10 insertions(+), 8 deletions(-)

http://git.horde.org/horde-git/-/commit/f47d1533998d3c270f2d4beb1de266e423a0411f

No, not using a Redis cluster. Just a very simple Redis install, then 
started with app defaults.

Re Jan's question, I have not had time to test with other caching 
backends at this stage.

Probably need http://redis.io/topics/data-types#sets

For some reason are you using a Redis cluster?  That's a fairly 
uncommon use case and most likely indicates your configuration is 
incorrect.  (Not to mention this limitation is mentioned nowhere in 
the API).

Even so, it looks like we will have to keep a list of Horde related 
cache keys in order to clear them.

Do you see this with other caching backends too?

I have Horde setup to use hash table and Redis.

If I change application level access permissions, the changes are not visible

If I disable Horde Cache, any changes to permissions apply 
immediately. Also if I run "redis-cli flushall" after making the 
permissions change it works.


It would appear that caching is not being notified of the changes.

If it is too complex to automate a cache-clear with permissions 
changes, perhaps an Apply button that does a cache-clear? Or at the 
very least commentary on the permissions page that changes may not 
take effect until cache is cleared.

I found this issue applied while setting / unsetting Guest permissions 
to Ansel and also to Wicked.

Whilst chasing down this one I also came on this:

horde-clear-cache
Are you sure you want to expire all cached data?
     (y) Yes
     (n) No

Type your choice [n]: y

====================

Fatal Error:
Cannot use KEYS with a cluster of connections
In /usr/share/pear/Predis/Connection/PredisCluster.php on line 135

1. Horde_Cache->clear() /usr/bin/horde-clear-cache:50
2. Horde_Cache_Storage_Hashtable->clear() /usr/share/pear/Horde/Cache.php:164
3. Horde_HashTable_Predis->clear() 
/usr/share/pear/Horde/Cache/Storage/Hashtabl
4. Predis\Client->keys() /usr/share/pear/Horde/HashTable/Predis.php:142
5. Predis\Client->__call() /usr/share/pear/Horde/HashTable/Predis.php:142
6. Predis\Connection\PredisCluster->executeCommand() 
/usr/share/pear/Predis/Cli
7. Predis\Connection\PredisCluster->getConnection() 
/usr/share/pear/Predis/Conn

====================