From 29bcf05fb844a7a76dca1f76fa22332e8dc04ade Mon Sep 17 00:00:00 2001
From: Keisuke Umegaki <41987730+keisku@users.noreply.github.com>
Date: Fri, 6 Dec 2024 21:46:23 +0900
Subject: [PATCH] Add `mysql.performance.performance_schema_digest_lost`
 (#19121)

* new metrics from Performance_schema_digest_lost

* fix tests

* add metric to metadata.csv

* changelog

* move to STATUS_VARS

* fix test
---
 mysql/changelog.d/19121.added       | 1 +
 mysql/datadog_checks/mysql/const.py | 2 ++
 mysql/metadata.csv                  | 1 +
 mysql/tests/variables.py            | 2 ++
 4 files changed, 6 insertions(+)
 create mode 100644 mysql/changelog.d/19121.added

diff --git a/mysql/changelog.d/19121.added b/mysql/changelog.d/19121.added
new file mode 100644
index 0000000000000..97990bdf0ca9b
--- /dev/null
+++ b/mysql/changelog.d/19121.added
@@ -0,0 +1 @@
+Add `mysql.performance.performance_schema_digest_lost`, the number of digest instances that could not be instrumented in the `events_statements_summary_by_digest` table.
diff --git a/mysql/datadog_checks/mysql/const.py b/mysql/datadog_checks/mysql/const.py
index fc2cb7d1f2e48..d69dc33dae014 100644
--- a/mysql/datadog_checks/mysql/const.py
+++ b/mysql/datadog_checks/mysql/const.py
@@ -39,6 +39,8 @@
     # Table Cache Metrics
     'Open_files': ('mysql.performance.open_files', GAUGE),
     'Open_tables': ('mysql.performance.open_tables', GAUGE),
+    # Performance schema metrics
+    'Performance_schema_digest_lost': ('mysql.performance.performance_schema_digest_lost', GAUGE),
     # Network Metrics
     'Bytes_sent': ('mysql.performance.bytes_sent', RATE),
     'Bytes_received': ('mysql.performance.bytes_received', RATE),
diff --git a/mysql/metadata.csv b/mysql/metadata.csv
index 4737e971e22c2..027b8ce425e3a 100644
--- a/mysql/metadata.csv
+++ b/mysql/metadata.csv
@@ -170,6 +170,7 @@ mysql.performance.max_prepared_stmt_count,gauge,,,,The maximum allowed prepared
 mysql.performance.open_files,gauge,,file,,The number of open files.,0,mysql,open files,
 mysql.performance.open_tables,gauge,,table,,The number of of tables that are open.,0,mysql,open tables,
 mysql.performance.opened_tables,gauge,,table,second,"The number of tables that have been opened. If `opened_tables` is big, your `table_open_cache` value is probably too small.",0,mysql,mysql performance opened_tables,
+mysql.performance.performance_schema_digest_lost,gauge,,,,The number of digest instances that could not be instrumented in the events_statements_summary_by_digest table. This can be nonzero if the value of performance_schema_digests_size is too small.,0,mysql,mysql performance performance schema digest lost,
 mysql.performance.prepared_stmt_count,gauge,,query,second,The current number of prepared statements.,0,mysql,current prepared statements,
 mysql.performance.qcache.utilization,gauge,,fraction,,Fraction of the query cache memory currently being used.,0,mysql,mysql performance qcache utilization,
 mysql.performance.qcache_free_blocks,gauge,,block,,The number of free memory blocks in the query cache.,0,mysql,mysql performance qcache_free_blocks,
diff --git a/mysql/tests/variables.py b/mysql/tests/variables.py
index 246616bc1c426..825c44307f76e 100644
--- a/mysql/tests/variables.py
+++ b/mysql/tests/variables.py
@@ -25,6 +25,8 @@
     # Table Cache Metrics
     'mysql.performance.open_files',
     'mysql.performance.open_tables',
+    # Performance schema metrics
+    'mysql.performance.performance_schema_digest_lost',
     # Network Metrics
     'mysql.performance.bytes_sent',
     'mysql.performance.bytes_received',