MySQL crashed suddenly
innodb_buffer_pool_size=27G is too close to the limit especially with a large amount of (max-)connections.
Lower this down and examine utilization. show global status like 'innodb_buffer_pool_pages% should be full after a reasonable amount of warmup (24hrs+)
show global status like 'innodb_buffer_pool_read%. read_requests vs reads should be quite large. (reads% &lt; 1%).
Once you have this balance hopefully there is sufficient ram available to avoid OOM, but still has sufficient performance.