Appendix A Configuration Keys

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Every key lives under Machine\System\eventd\. eventd ignores unknown keys in the subtree. An invalid value is ignored and the value already in use is retained, and eventd emits a synthetic.config_change event for every change actually applied (§8.3).

A.1 Required #

No compiled-in defaults. A missing or invalid value fails startup (§8.2).

Key	Type	Description
`EventStorePath`	REG_SZ	Directory for the event shard databases and `eventd-meta.db`.
`LogStorePath`	REG_SZ	File path for the log store database.
`MetricStorePath`	REG_SZ	File path for the metric store database.
`QuerySocketPath`	REG_SZ	Unix socket path for queries.
`LogSocketPath`	REG_SZ	Unix socket path for log ingestion.
`MetricSocketPath`	REG_SZ	Unix socket path for metric ingestion.

A.2 SQLite storage #

Key	Type	Default	Range	Description
`WalCheckpointPages`	REG_DWORD	1000	100–100000	WAL page threshold triggering a passive checkpoint, on shard, log, metric and metadata databases alike.

A.3 Event ingestion #

Key	Type	Default	Range	Description
`StorageShards`	REG_DWORD	0	0–256	Number of event shards. 0 means the CPU count.
`MaxBatchSize`	REG_DWORD	10000	100–100000	Maximum events per writer transaction.
`MaxBatchLatencyMs`	REG_DWORD	100	10–5000	Maximum ms before an event batch commits.

A.4 Log ingestion #

Key	Type	Default	Range	Description
`LogMaxBatchSize`	REG_DWORD	5000	100–100000	Maximum log records per transaction.
`LogMaxBatchLatencyMs`	REG_DWORD	500	10–5000	Maximum ms before a log batch commits.
`MaxLogDatagramBytes`	REG_DWORD	262144	4096–1048576	Maximum accepted log datagram size.

A.5 Metric ingestion #

Key	Type	Default	Range	Description
`MetricMaxBatchSize`	REG_DWORD	5000	100–100000	Maximum metric samples per transaction.
`MetricMaxBatchLatencyMs`	REG_DWORD	1000	10–5000	Maximum ms before a metric batch commits.
`MaxMetricDatagramBytes`	REG_DWORD	262144	4096–1048576	Maximum accepted metric datagram size.
`MetricSeriesCacheSize`	REG_DWORD	50000	1000–1000000	Entries in the LRU series resolution cache.

A.6 Adaptive indexing #

Key	Type	Default	Range	Description
`AdaptiveIndexWindowHours`	REG_DWORD	24	1–168	Rolling window over which query frequency is measured.
`AdaptiveIndexPolicyIntervalMinutes`	REG_DWORD	60	60–1440	How often the desired index set is recomputed. The minimum of 60 prevents index churn.
`AdaptiveIndexCreateThreshold`	REG_DWORD	100	10–10000	Queries on a field within the window needed to add it.
`AdaptiveIndexDropThreshold`	REG_DWORD	10	1–1000	Queries below which it is removed. Less than the create threshold, which is what supplies the hysteresis.

A.7 Index shedding #

Key	Type	Default	Range	Description
`SheddingWindowSeconds`	REG_DWORD	30	10–300	Sliding window for graduated shedding.
`SheddingBatchPercent`	REG_DWORD	75	50–100	Percentage of batches in the window exceeding 75% of `MaxBatchSize` that triggers graduated shedding.
`EmergencySheddingBufferPercent`	REG_DWORD	75	50–95	Ring buffer fill percentage triggering emergency shedding.

A.8 Adaptive rollups #

Key	Type	Default	Range	Description
`AdaptiveRollupWindowHours`	REG_DWORD	48	1–168	Rolling window for rollup query frequency.
`AdaptiveRollupScalarWindowSeconds`	REG_DWORD	300	60–86400	Base window used when a scalar range query triggers rollup creation.
`AdaptiveRollupCreateThreshold`	REG_DWORD	50	10–10000	Queries needed to trigger rollup computation.
`AdaptiveRollupDropThreshold`	REG_DWORD	5	1–1000	Frequency below which a pair leaves the registry. Less than the create threshold.

A.9 Retention #

Key	Type	Default	Range	Description
`EventRetentionDays`	REG_DWORD	30	1–3650	Maximum age of events.
`EventRetentionMaxBytes`	REG_QWORD	0	0–2^64−1	Maximum total logical live size of the event shards. 0 means no limit.
`LogRetentionDays`	REG_DWORD	14	1–3650	Maximum age of log entries.
`LogRetentionMaxBytes`	REG_QWORD	0	0–2^64−1	Maximum logical live size of the log store. 0 means no limit.
`MetricRetentionDays`	REG_DWORD	90	1–3650	Maximum age of metric samples.
`MetricRetentionMaxBytes`	REG_QWORD	0	0–2^64−1	Maximum logical live size of the metric store. 0 means no limit.
`RetentionCheckIntervalMinutes`	REG_DWORD	60	1–1440	How often the retention thread runs.
`RetentionDeleteBatchRows`	REG_DWORD	10000	100–100000	Maximum rows deleted in one retention transaction.

A.10 Querying #

Key	Type	Default	Range	Description
`QueryTimeoutMs`	REG_DWORD	30000	1000–300000	Maximum query execution time.
`MaxConcurrentQueries`	REG_DWORD	128	1–4096	Concurrent queries globally, streaming and non-streaming.
`MaxStreamingQueries`	REG_DWORD	64	1–1024	Concurrent streaming queries globally.
`MaxDistinctStreamValues`	REG_DWORD	100000	1000–10000000	Values tracked by one DISTINCT streaming query.
`MaxQueryMessageBytes`	REG_DWORD	65536	1024–16777216	Maximum query request or response payload.

A.11 Cross-type filtering #

Key	Type	Default	Range	Description
`CrossTypeWindowMs`	REG_DWORD	15000	1000–300000	Centred window for cross-type event and log existence checks.
`CrossTypeMaxLookbackSeconds`	REG_DWORD	604800	3600–2592000	Maximum range a cross-type filter may scan.

A.12 The security subtree #

Read-path descriptors live under Machine\System\eventd\Security\ and are not configuration in the sense above (§7.2):

Machine\System\eventd\Security\Events\*
Machine\System\eventd\Security\Events\<pattern>
Machine\System\eventd\Security\Logs\*
Machine\System\eventd\Security\Logs\<pattern>
Machine\System\eventd\Security\Metrics\*
Machine\System\eventd\Security\Metrics\<pattern>

The administrative descriptor is not here; it is admin_sd in eventd-meta.db (§3.5).

A.13 When a change takes effect #

Change	Effect
Every tuning parameter above	Applied immediately.
Socket paths	Restart.
Store paths	Restart.
`StorageShards`	Restart.
Security descriptors	Next query; the registry watch invalidates the cache.

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