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Alerts and Notifications: Configuration

Performance hint configuration keys​

  • Most of the keys below set the threshold at which a performance hint is raised.

  • The last two keys have other roles: PerformanceHints.Documents.HugeDocumentsCollectionSize sets the size of a list collected for debugging, and PerformanceHints.Memory.MinSwapSizeInMb sets the threshold of a low-swap alert.

PerformanceHints.Documents.HugeDocumentSizeInMb​

A huge-documents performance hint is raised when a stored document is larger than the set size.

  • Type: int
  • Default: 5
  • Scope: Server-wide or per database

PerformanceHints.Indexing.AlertWhenSourceDocumentIncludedInOutput​

An indexing performance hint is raised when an index stores whole source documents in its entries.
Set the key to false to disable this hint.

  • Type: bool
  • Default: true
  • Scope: Server-wide or per database

PerformanceHints.Indexing.MaxDepthOfRecursionInLinqSelect​

An indexing performance hint is raised when a LINQ index definition contains more let clauses than the set number.

  • Type: int
  • Default: 32
  • Scope: Server-wide or per database

PerformanceHints.Indexing.MaxIndexOutputsPerDocument​

An indexing performance hint is raised when an index produces more index entries from a single document than the set number.
Set the key to 0 or to a negative number to disable this hint.

  • Type: int
  • Default: 1024
  • Scope: Server-wide or per database

PerformanceHints.Indexing.MaxNumberOfLoadsPerReference​

An indexing-references performance hint is raised when the number of times an index loads the same related document or compare-exchange value reaches the set number.

  • Type: int
  • Default: 1024
  • Scope: Server-wide or per database

PerformanceHints.MaxNumberOfResults​

A paging performance hint is raised when a request returns more results than the set number.

  • Type: int
  • Default: 2048
  • Scope: Server-wide or per database

PerformanceHints.TooLongRequestThresholdInSec​

A request-latency performance hint is raised when a request takes longer than the set time.

  • Type: int
  • Default: 30
  • Scope: Server-wide or per database

PerformanceHints.Documents.HugeDocumentsCollectionSize​

Each document detected as huge is recorded in memory, with the document's ID, its size, and the time it was detected.
This key sets the number of records kept: once the number is exceeded, the oldest records are dropped as new records are added.
The records are returned by the /databases/*/debug/documents/huge debug endpoint and are collected into the debug package.
This key does not affect the list of occurrences shown in the hint itself, which is capped separately at 100 documents.

  • Type: int
  • Default: 100
  • Scope: Server-wide or per database

PerformanceHints.Memory.MinSwapSizeInMb​

This key sets the threshold of an alert, not of a performance hint, although it belongs to the PerformanceHints category.
On a Linux server, the alert is raised when the swap size is more than 128 MB below the set minimum.
The alert is a server-wide Warning, titled Low swap size, or No swap file when the machine has no swap space at all.
Note that the swap size is checked once, when the server starts, and that the check is skipped when RavenDB runs in a Docker container.

  • Type: int
  • Default: On Linux, set when the server starts: 1024 (1 GB) when the machine has less than 8 GB of RAM, otherwise half the machine's RAM, up to 8192 (8 GB).
  • Scope: Server-wide only

Filtering out notifications​

  • To keep chosen notifications from appearing in the notification center, list them in the Notifications.FilterOut configuration key.
    Each entry names a whole notification type, a performance-hint reason, or an alert reason.

    Example: Filter out all performance hints and the low-swap alert​

    {
        "Notifications.FilterOut": "PerformanceHint;LowSwapSize"
    }

  • A dropped notification is neither stored nor shown, and is left out of the alert and hint counts reported in the databases list view, over the monitoring endpoints, and over SNMP.

  • The key is server-wide and cannot be set for a specific database.

  • Learn the values the key accepts, and see more examples, in the notification center article.

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