<!--
Copyright 2020 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->
<!--
This file is used to generate a comprehensive list of Simple histograms
along with a detailed description for each histogram.
For best practices on writing histogram descriptions, see
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md
Please follow the instructions in the OWNERS file in this directory to find a
reviewer. If no OWNERS file exists, please consider signing up at
go/reviewing-metrics (Googlers only), as all subdirectories are expected to
have an OWNERS file. As a last resort you can send the CL to
[email protected].
-->
<histogram-configuration>
<histograms>
<histogram base="true" name="SimpleCache.CacheSizeOnInit" units="KB"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The size of the cache at the time that the index has finished initializing.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.ConsistencyResult"
enum="SimpleCacheConsistencyResult" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Record the outcome of the simple DiskCache consistency check. The
consistency check is executed every time a simple DiskCache is initialized.
This check includes both inspecting the schema on disk and upgrading the
schema to the latest version if necessary.
</summary>
</histogram>
<histogram base="true"
name="SimpleCache.ConsistencyResultAfterIndexFilesDeleted"
enum="SimpleCacheConsistencyResult" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Record the final consistency check value after index files have been deleted
from an empty simple DiskCache. This histogram will tell us how often the
index deletion code results in a functioning cache. It will also tell us
what kind of consistency failures cannot be recovered due to index file
deletion.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.CreationToIndex" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time from the creation of the simple cache backend until the index has
been loaded from disk.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.CreationToIndexFail" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time from the creation of the simple cache backend until the index fails
to load.
</summary>
</histogram>
<histogram base="true"
name="SimpleCache.DidDeleteIndexFilesAfterFailedConsistency" enum="Boolean"
expires_after="2023-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Record if any simple DiskCache index files were deleted from an otherwise
empty cache after the cache failed the initialization consistency check.
This histogram will tell us how often the deletion code is triggering and
modifying the disk.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.DiskCloseLatency" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time to close (write out footers and close the file) the cache entry on
disk. Includes only successful operations.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.DiskCreateLatency" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time to access (open for creation and write initial headers) the cache
entry on disk. Includes only successful operations.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.DiskDoomLatency" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time to remove the cache entry on disk. Includes only individually
doomed entries, not entries bulk-erased during eviction.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.DiskOpenLatency" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time to access (open and read headers from all files) the cache entry on
disk. Includes only successful operations.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.DiskWriteLatency" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time to write a chunk to the cache entry on disk. Includes only
successful operations.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.EntryCreationTime" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time, in ms, spent creating a new entry on disk. This measures time from
when the method got removed from SimpleEntryImpl's operation queue till when
the callback is about to be invoked, and includes all Open and Create
operations, despite what the name may suggest.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.Eviction.EntryCount" units="units"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>The number of entries to be erased in an eviction.</summary>
</histogram>
<histogram base="true" name="SimpleCache.Eviction.TimeToDone" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>Time spent completing an eviction.</summary>
</histogram>
<histogram base="true" name="SimpleCache.Eviction.TimeToSelectEntries"
units="ms" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>Time spent selecting entries for eviction.</summary>
</histogram>
<histogram name="SimpleCache.FileDescriptorLimiterAction"
enum="SimpleCache.FileDescriptorLimiterOp" expires_after="2022-11-13">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
This even is emitted when SimpleCache is forced to either close some files
due to being over FD limit, or reopen files it had to close due to such
limit earlier.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.HeaderSize" units="bytes"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The size of the header stream of a Simple Cache entry, emitted every time
the headers are written or rewritten.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.IndexCreatedEntryCount" units="units"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>The number of entries in a newly created index file.</summary>
</histogram>
<histogram base="true" name="SimpleCache.IndexFileStateOnLoad"
enum="SimpleIndexState" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The state the index file is at when an attempt is made to load from it.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.IndexInitializeMethod"
enum="SimpleCacheIndexInitializeMethod" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>The method used to initialize the simple cache index.</summary>
</histogram>
<histogram base="true" name="SimpleCache.IndexNumEntriesOnInit" units="entries"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The number of entries in the index at the time that the index has finished
initializing.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.IndexRestoreTime" units="ms"
expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Time (as measured on the worker pool) spent restoring the index file by
iterating directory entries.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.OpenEntryIndexState"
enum="SimpleCacheOpenEntryIndexState" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
At the time that an entry is opened, the state of that entry in the index.
</summary>
</histogram>
<histogram base="true"
name="SimpleCache.OriginalConsistencyResultBeforeSuccessfulRetry"
enum="SimpleCacheConsistencyResult" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Record the original consistency error produced by a simple DiskCache before
a retry was attempted and succeeded. This histogram will tell us what kind
consistency errors can be recovered from in practice.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.RetryConsistencyResult"
enum="SimpleCacheConsistencyResult" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Record the outcome of the simple DiskCache consistency check after retrying
initialization on an empty cache directory. The retry may occur after
corrupt index files were deleted from an empty cache. The retry may also
occur if the original failed initialization left an empty directory without
any index files. This histogram will tell us how often the retry succeeds in
recovering caches and also which consistency checks cannot be recovered.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.StaleIndexExtraEntryCount"
units="entries" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Count of the number of entries recorded in the index, but not actually
present in the cache. Recorded each time a stale index is found and a
directory rescan is required.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.StaleIndexMissedEntryCount"
units="entries" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Count of the number of entries present in a cache, but not recorded in the
index. Recorded each time a stale index is found and a directory rescan is
required.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.StaleIndexQuality"
enum="SimpleCacheStaleIndexQuality" expires_after="2024-12-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The quality of a "stale" index compared to a full directory
rescan. Recorded immediately after every directory scan for stale indexes.
</summary>
</histogram>
<histogram base="true" name="SimpleCache.SyncOpenPrefetchMode"
enum="SimpleCachePrefetchMode" expires_after="2023-12-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The kind of prefetching performed, if any, when executing
SimpleSynchronousEntry::ReadAndValidateStream0AndMaybe1().
</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.Event"
enum="SimpleGeolocationRequestEvent" expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>Events in reqests processing of IP-based SimpleGeolocation.</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.HasCellTowers"
enum="SimpleGeolocationRequestHasCellTowers" expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
This boolean histogram counts SimpleGeolocationRequests carrying a nonzero
number of cell towers.
</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.HasWiFiAccessPoints"
enum="SimpleGeolocationRequestHasWiFiAccessPoints" expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
This boolean histogram counts SimpleGeolocationRequests carrying nonzero
number of WiFi access points.
</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.ResponseCode"
enum="HttpResponseCode" expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>Http response codes in IP-based SimpleGeolocation.</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.ResponseFailureTime" units="ms"
expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time elapsed between the sending of the first API request and the time
the final (failed) response was recorded. Includes all retries.
</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.ResponseSuccessTime" units="ms"
expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The time elapsed between the sending of the first API request and the time
the final (successfull) response was recorded. Includes all retries.
</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.Result"
enum="SimpleGeolocationRequestResult" expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>Result of SimpleGeolocationRequest.</summary>
</histogram>
<histogram name="SimpleGeolocation.Request.Retries" units="units"
expires_after="never">
<!-- expires-never: This reports external location provider health status and
should be kept until we use this API. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>Number of retries until the final response was recorded.</summary>
</histogram>
</histograms>
</histogram-configuration>
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