WAIT_XTP_HOST_WAIT is recorded when a thread waits for an In-Memory OLTP operation that was initiated by the regular database engine and implemented by the XTP host layer, the bridge through which the traditional engine and the in-memory engine cooperate. Cross-engine housekeeping lands its wait time here.
Another member of the XTP background family, present wherever memory-optimized structures exist.
Is It a Problem?
No; it has not been a contention point and is filtered as benign. Its amounts track how often the two engines coordinate, which scales with XTP usage but not with any fault condition.
In-Memory OLTP performance questions have concrete homes: garbage collection stats (sys.dm_xtp_gc_queue_stats), checkpoint file health, native procedure stats, and memory consumption of memory-optimized tables (sys.dm_db_xtp_table_memory_stats). This wait features in none of those investigations.
Common Causes
- Normal engine-to-XTP-host coordination on databases with memory-optimized objects.
What To Do
- Filter it out of wait analysis.
- Investigate XTP topics through the feature’s own DMVs when needed.
How To See It
Rank waits with Get-WaitStatistics, where it is filtered as XTP background machinery.
Part of the SQL Server Wait Types Library.
Related deep dive: WRITELOG Wait Type.
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