Can you share steps to reproduce, please?
And, just to confirm, the cache key you’re trying to increment already exists? wp_cache_incr() requires the key to already exist with a value:
public function incr( $key, $offset = 1, $group = 'default' ) {
if ( empty( $group ) )
$group = 'default';
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
$key = $this->blog_prefix . $key;
if ( ! $this->_exists( $key, $group ) )
return false;
Thread Starter
gioni
(@gioni)
Thanks, I’ll try the code you’ve suggested.
To be exact I’m trying to get the plugin working together with Batcache https://ww.wp.xz.cn/plugins/batcache/. Batcache uses object cache to store rendered pages. To clear the cache it uses the following code
$url_key = md5( $url );
wp_cache_add("{$url_key}_version", 0, $batcache->group);
$retval = wp_cache_incr("{$url_key}_version", 1, $batcache->group);
It seems that code is not working now because I’m unable to clear the cache this way.
That’s odd.
Can you debug a bit further into the object cache code to see where specifically it might be failing?
Thread Starter
gioni
(@gioni)
Hi, Daniel!
It seems that it’s solved. There was an issue with default REDIS configuration. Sometimes REDIS wrote to the log: “Can’t save in background: fork: Cannot allocate memory”. After I had allowed overcommitting memory the issue was gone.
Just in case:
1. Add vm.overcommit_memory = 1 to /etc/sysctl.conf
2. Run the command sysctl vm.overcommit_memory=1
Glad you were able to sort it out, @gioni. When in doubt, always check the logs 🙂
