[receiver/mysql] fix oob overflow for Innodb_buffer_pool_pages_misc

Author: atoulme

.chloggen/mysql_oob_misc.yaml

@@ -0,0 +1,29 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: mysqlreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Avoid recording a value for the MysqlBufferPoolPages metric when out-of-bounds.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35495]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  When using compressed tables, Innodb_buffer_pool_pages_misc may report an out-of-bounds value.
+  See https://bugs.mysql.com/bug.php?id=59550 for context.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

receiver/mysqlreceiver/scraper.go

@@ -139,9 +139,13 @@ func (m *mySQLScraper) scrapeGlobalStats(now pcommon.Timestamp, errs *scrapererr
 			addPartialIfError(errs, m.mb.RecordMysqlBufferPoolPagesDataPoint(now, v,
 				metadata.AttributeBufferPoolPagesFree))
 		case "Innodb_buffer_pool_pages_misc":
+			_, err := strconv.ParseInt(v, 10, 64)
+			if err != nil {
+				m.logger.Warn("Innodb_buffer_pool_pages_misc reports an out-of-bounds value and will be ignored. See https://bugs.mysql.com/bug.php?id=59550.")
+				continue
+			}
 			addPartialIfError(errs, m.mb.RecordMysqlBufferPoolPagesDataPoint(now, v,
 				metadata.AttributeBufferPoolPagesMisc))
-
 		// buffer_pool.page_flushes
 		case "Innodb_buffer_pool_pages_flushed":
 			addPartialIfError(errs, m.mb.RecordMysqlBufferPoolPageFlushesDataPoint(now, v))

receiver/mysqlreceiver/scraper_test.go

@@ -125,6 +125,35 @@ func TestScrape(t *testing.T) {
 	})
 }
 
+func TestScrapeBufferPoolPagesMiscOutOfBounds(t *testing.T) {
+
+	expectedFile := filepath.Join("testdata", "scraper", "expected_oob.yaml")
+	expectedMetrics, err := golden.ReadMetrics(expectedFile)
+	cfg := createDefaultConfig().(*Config)
+	cfg.Username = "otel"
+	cfg.Password = "otel"
+	cfg.AddrConfig = confignet.AddrConfig{Endpoint: "localhost:3306"}
+
+	scraper := newMySQLScraper(receivertest.NewNopSettings(), cfg)
+	scraper.sqlclient = &mockClient{
+		globalStatsFile:             "global_stats_oob",
+		innodbStatsFile:             "innodb_stats_empty",
+		tableIoWaitsFile:            "table_io_waits_stats_empty",
+		indexIoWaitsFile:            "index_io_waits_stats_empty",
+		tableStatsFile:              "table_stats_empty",
+		statementEventsFile:         "statement_events_empty",
+		tableLockWaitEventStatsFile: "table_lock_wait_event_stats_empty",
+		replicaStatusFile:           "replica_stats_empty",
+	}
+
+	scraper.renameCommands = true
+
+	actualMetrics, err := scraper.scrape(context.Background())
+	require.NoError(t, err)
+	require.NoError(t, pmetrictest.CompareMetrics(actualMetrics, expectedMetrics,
+		pmetrictest.IgnoreMetricDataPointsOrder(), pmetrictest.IgnoreStartTimestamp(), pmetrictest.IgnoreTimestamp()))
+}
+
 var _ client = (*mockClient)(nil)
 
 type mockClient struct {