Yac Object Cache

Yac keeps the cache in a shared memory segment accessible to all PHP workers, so a read is a hash lookup in local memory — no cache server, no socket, no network.

Highlights

• Fast. No socket, no network, no global lock, so throughput scales with workers. Yac’s own benchmark measured 13x-70x higher ops/s than APCu and 170x-730x higher than local Memcached, depending on value size. On the author’s own site (www.laruence.com) that translated to page renders coming out 19% faster than with the Memcached drop-in.
• Nothing to operate. No cache server to install, secure, monitor or restart.
• Health you can read. Hit rate, hits and misses charted over Today / Yesterday / Last 7 days, with a diagnosis that also says when not to add memory.
• Fails soft. No extension, or yac.enable=0, degrades to a per-request cache and the site keeps serving.

Best fit

Single-node or few-node installs where all PHP workers share a machine. For multi-server clusters needing cross-node consistency, a network cache (Memcached/Redis) suits better.