Appendix 3.A Limits

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Every bound this chapter requires a collector to enforce, with the value and adjustable range of the mainline collector. The mainline values are informative: a conforming collector chooses its own, and a producer or client MUST NOT depend on any of them (§3.29).

The mainline configuration key names are those of eventd, whose configuration is catalogued in the eventd TRMP §A.

3.A.1 Ingestion #

Bound	Mainline value	Mainline range	Key	Section
Log datagram ceiling	262144 B	262144 – 1048576	`MaxLogDatagramBytes`	§3.6
Metric datagram ceiling	262144 B	262144 – 1048576	`MaxMetricDatagramBytes`	§3.9
Receive queue, either socket	≤ 4 × the ceiling	—	—	§3.6

3.A.2 Queries #

Bound	Mainline value	Mainline range	Key	Section
Query request ceiling	65536 B	1024 – 16777216	`MaxQueryRequestBytes`	§3.15
Query response target	65536 B	1024 – 16777216	`QueryResponseTargetBytes`	§3.15
Query timeout	30000 ms	1000 – 300000	`QueryTimeoutMs`	§3.16
Concurrent queries	128	1 – 4096	`MaxConcurrentQueries`	§3.14
Concurrent streaming queries	64	1 – 1024	`MaxStreamingQueries`	§3.14
Concurrent queries per caller	16	1 – 4096	`MaxQueriesPerUser`	§3.14
Memory all running queries hold together	268435456 B	16777216 – 4294967295	`MaxQueryHeldBytes`	§3.16
Values per DISTINCT stream	100000	1000 – 10000000	`MaxDistinctStreamValues`	§3.27

3.A.3 Cross-type filtering #

Bound	Mainline value	Mainline range	Key	Section
Existence window `W`	15000 ms	1000 – 300000	`CrossTypeWindowMs`	§3.26
Maximum lookback	604800 s	3600 – 2592000	`CrossTypeMaxLookbackSeconds`	§3.26

3.A.4 Fixed by this chapter #

These are not configuration and a collector MUST NOT vary them.

Quantity	Value	Section
Timestamp domain	`0` – `9223372036854775807` ns	§3.5
GUID field width	16 bytes	§3.7, §3.11
Message length prefix	4 bytes, little-endian	§3.15
Maximum response payload	`2^32 - 1` bytes	§3.15
Transforms per query	at most 1	§3.25
Terminal aggregations per query	at most 1	§3.25
Queries per connection	exactly 1	§3.14

The response target is not a ceiling. A complete record larger than the target travels alone, so the configurable ingestion ceilings do not need to be coupled to it (§3.15).

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