The Terracotta custom installation allows products such as Ehcache and Quartz to run in a Terracotta cluster using Distributed Shared Objects (DSO). A cluster with DSO can distribute Terracotta products along with custom POJOs and object-graph roots, as well as integrate with other technolgies using Terracotta Integration Modules (TIMs).
Terracotta DSO clusters differ from non-DSO clusters in certain important ways. In DSO clusters, objects have identity, shared classes must be portable and marked for instrumentation, and locks are distributed. Cluster-wide locking requirements are stricter and more extensive with DSO.
Use the custom installation if your deployment requires the features of DSO.
If you are new to Terracotta, see this introduction to the Terracotta platform before proceeding with the custom installation. For more information on comparing custom and express installation methods, see Express Versus Custom Installations.
There are two ways to install the Terracotta products: Express and Custom. The express installation is recommended for users who can cluster without DSO. For example, the express intallation of Distributed Ehcache is recommended for clustering a cache only. The custom installation is for users who also require DSO features such as Terracotta roots, clustering of Java objects (for example, custom POJOs), preservation of object identity, or integration of other technologies using Terracotta Integration Modules (TIMs).
If you are using Ehcache on a single JVM, for example, or used cache replication for clustering, consider the express installation (see Distributed Ehcache Express Installation). If you are a current Terracotta user who requires DSO and distributed caching, you may need the custom installation given in this document.
If you are unsure about which installation path to choose, read both installation documents to find the one that meets your requirements. These installation paths are not compatible and cannot be used in combination .
