Why MySQL Restarted When Number of Processes Running Now 0 How To fix this issue
You have assigned very low RAM 128MB to innodb_buffer_pool_size (which is default RAM). So you should assign approx. 80% of total RAM to this variable if you are using innodb engine, as mysql uses intially memory from this variable to cache index as well data in innodb engine.
So update at least 1 GB RAM (should be 80% of total ram for innodb) to
innodb_buffer_pool_size in your config file and restart mysql service.
You have 1 GB RAM: You can assign 800M RAM (or >=500M) to
MySQL will auto restart when number of running process 0: As per errors shared by you…this error is coming at the time of mysql service start and server is not able to initiate mysql service with such a less RAM.
160103 18:39:55 InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137756672 bytes) failed; errno 12
160103 18:39:55 InnoDB: Completed initialization of buffer pool
160103 18:39:55 InnoDB: Fatal error: cannot allocate memory for the buffer pool