Next generation JIAJIA (SDSM) --- JIAJIA3.0

JIAJIA is a software distributed shared memory system that written at the beginning of the century. What makes it unique is its lock-based consistency.

As a static library, it provide some usable interfaces to programmer so that they can use it divide their task to run on multiple machines. Interfaces

What I want to do is mainly include these aspects:

• Upgrade it so that it can be adapted to 64-bit machines
• Redesign some interfaces to increase usability (eg. replace signal-driven IO with event-driven IO epoll in linux system)
• Optimize cache design to support LRU
• Memory pool support to provide finer-grained control on memory allocation
• Adopt RDMA technology to redesign the whole system desing (two directions)
  • RDMA support as a extra function that can be truned on or off. It means that there are two side-by-side network protocol stacks in the system, and will use RDMA first if possible.
  • Pure RDMA (pursue extreme performance)
• The last one need to consider is its availability (fault tolerance), consider checkpoint/restore(store it's memory content to persistent storage periodically)

JIAJIA3.0 Interfaces

/**
 * @brief Initialize JIAJIA3.0
 * copy the application to hosts specified in .jiahosts file; 
 * initializes internal data structures of JIAJIA3.0
*/
void jia_init(int argc, char **argv);

/**
 * @brief Exit JIAJIA3.0
 */
void jia_exit();

jia_init() should be called before any other JIAJIA3.0 functions.
jia_end() should be called at the end of your program.

/**
 * @brief Allocate size bytes memory across the hosts
 */
unsigned long jia_alloc(size_t size);

jia_alloc() will be expanded to be more feature-rich and intelligent.

/**
 * jia_lock -- acquire the lock indentified by lockid
 * @lockid: the lock id
 */

void jia_lock(int lockid);

/**
 * jia_unlock -- release the lock indentified by lockid
 * @lockid: the lock id
 */
void jia_unlock(int lockid);

/**
 * jia_barrier -- perform a global barrier
 */
void jia_barrier();

Note: jia_barrier() cannot be called inside a critical section enclosed by jia_lock() and jia_unlock()

Work up to Now

• Upgrade origin code with detailed comments
• Remove obsolete code (functions or usages) snippets
• Adapt it to 64bit machine (redesign msg structure)
• Some tests (IPoIB vs traditional TCP/IP stack performance comparsion)
• Blueprints of JIAJIA3.0

Usage