Devoxx 2013: HTTP Caching in Practice

Xavier Coulon

types of cache:

• local cache
• proxy cache
• gateway cache
• (app cache -- custom built in the app)

http1.1 caching GET requests

• expiration Last-Modified + Expires headers
• If-Modified-Since header -> 304 not modified
• ETag header
• If-Match & 412 Precondition failed.

prevent inconsistencies: use explicit directives

• Cache-Control
  • request header: no-cache, max-age, no-store, max-stale, min-fresh, no-transform & only ..
  • response: public, private, no-cache, proxy-revalidate, max-age,...
• pragma header, request & response: no-cache: only for http 1.0 backwards compatiblity.
• Refresh button in brower adds Cache-Control and Pragma headers to request. (not in Ajax requests!

java helpers:

• Servlet Filter
• JAX-RS 2.0: interceptors: Ajax-specific (e.g. add ETag + send Status.NOT_MODIFIED)
• testing:
  • Arquillian (+ REST extension)
  • REST-assured

Https:

• proxy caching doesn't work
• decide on using http for static resources...

caching strategy:

• static content:
  • max cache usage
  • enable gateway caching: Cache-Control: public, max-age
• dynamic content:
  • timeout or ETag

RFC 2616 spec (http 1.1): http://www.ietf.org/rfc/rfc2616.txt

Devoxx11: Real-world deep-dive into Infinispan - the open source data grid platform

Sanne Grinovero, Pete Muir and Mircea Markus
Infinispan details

• developed & provided by JBoss
• Open Source license
• distributed, in-memory data structure
• High Available: configuration options depending on your safety / performance considerations
  • Total replication
  • Partial replication ("distribution mode")
• Elastic:
  • easy to scale up / down
  • deal with node stops / crashes
  • accept additional nodes
  • managed through JGroups

Capabilities:

• Transactions
• Map / Reduce
• Query
• JMX access

Two access modes to inifinispan:

• embedded mode: in the JVM
• client / server mode: different protocols supported:
  • REST
  • memcached
  • hotrod

Possible setups:

• local cache: Simple Map-like interface, with advanced cache-features (eviction, etc.)
• cluster cache: all caches are kept in sync between JVM's, the developer is responsible for accessing the persistence layer (DB)
• grid cache: the cache itself handles the persisting of the data to the DB.

JGroups

• reliable cluster communication
• developed by JBoss, and used by Infinispan
• Node / cluster config (incl. auto-discover setup)
• focus on performance: e.g. UDP, but with reliability handled by JGroups
• support for reliable multicast messages