Limits

The tables below provide guidance on HSE operating limits. A few are enforced, but most are based on testing and experience.

The limits appropriate for a specific HSE client application are largely dependent on the performance requirements of that application, and the hardware it runs on.

Feel free to push these limits in a test environment, and let us know how far you get and what you observe.

KVDB Limits

Entity	Description	Limit	Enforced
KVDB count	Active KVDB per system	8	No
KVS count	KVS in a KVDB	16	No
Key count	Total keys in a KVDB (billions)	200	No
Capacity	Total storage capacity of a KVDB (TB)	12	No
Transaction count	Concurrent transactions in a KVDB	1,000 per CPU	Yes
Cursor count	Concurrent cursors in a KVDB	10,000	No

Tip

An active cursor can consume up to 2MB of memory.

KVS Limits

Entity	Description	Limit	Enforced
Key size	Range of valid key sizes (bytes)	1 – 1,334	Yes
Value size	Range of valid value sizes (bytes)	0 – 1MiB	Yes
Key count	Total keys in a KVS (billions)	50	No
Capacity	Total storage capacity of a KVS (TB)	4	No
Cursor count	Concurrent cursors in a KVS	8,000	No

Mpool Limits

These mpool limits apply only to HSE as an mpool client application. Other mpool client applications may have vastly different mpool limits.

Entity	Description	Limit	Enforced
Media class capacity	Volume size storing a media class (TB)	8	No
Mpool capacity	Combined capacity of all media classes (TB)	16	No