Overall Architecture

Figure 1 Overall architecture of BoostIO

Table 1 describes the logical elements contained in the preceding architecture.

**Table 1** Logical elements
Module Name	Description
Cache client (SDK)	Provides C APIs and works as the entry to the BoostIO distributed cache. It is responsible for instance management, network resource management, node/partition view management, and traffic control.
Data mirroring module (Mirror)	Manages multi-copy redundancy and distributes requests for cache objects.
Write cache module (WriteCache)	Manages write cache object data, index metadata, and eviction policies, and supports data write-back and write-through modes.
Read cache module (ReadCache)	Manages read cache object data, index metadata, and eviction policies, and supports object data prefetch.
Flow space module (Flow)	Provides APIs for applying for and releasing the infinite logical linear space and supports data write in append mode.
Memory space management module (MM)	Manages the cache memory space by block. The memory can be registered with RDMA and Shmemory.
Drive block device management module (BDM)	Manages the cache drive space by block, and supports synchronous and asynchronous data read/write.
Back-end storage management module (UFS)	Manages multiple types of back-end storage systems. It provides a unified data access API to mask differences between various back-end storage systems.
Cluster management module (CM)	Manages cache clusters based on the open source software ZooKeeper, including status monitoring, partition view calculation, and troubleshooting.

Parent topic: Feature Description