InnoDB Insert Buffer Merge Backlog
infoInnoDB change buffer (insert buffer) accumulating changes faster than they can be merged to secondary indexes. Large change buffer improves write performance but can cause read stalls and long crash recovery times.
mysql.innodb.ibuf_size > 1000 pages and increasing, with mysql.innodb.ibuf_merges rate low relative to mysql.innodb.ibuf_merged inserts, or mysql.innodb.ibuf_segment_size growing
Large change buffer is normal during bulk inserts but can indicate issues if persistent. Review innodb_change_buffer_max_size - default 25% of buffer pool may be too high if change buffer grows large. Monitor merge rate: mysql.innodb.ibuf_merged_delete_marks, mysql.innodb.ibuf_merged_deletes, mysql.innodb.ibuf_merged_inserts. If change buffer size is problematic (e.g., causing long recovery times during testing), consider: 1) Reduce innodb_change_buffer_max_size, 2) Increase innodb_io_capacity to allow faster merges, 3) Review workload for pathological cases (e.g., inserts to secondary indexes in random order).