feat(mysqlreceiver): Add mysql.connection.errors metric

Signed-off-by: Dominik Rosiek <drosiek@sumologic.com>

.chloggen/drosiek-mysql-connection-errors.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# 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: Add mysql.connection.errors metric
+
+# One or more tracking issues related to the change
+issues: [14138]
+
+# (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:

receiver/mysqlreceiver/documentation.md

@@ -15,6 +15,7 @@ These are the metrics available for this scraper.
 | **mysql.buffer_pool.pages** | The number of pages in the InnoDB buffer pool. | 1 | Sum(Int) | <ul> <li>buffer_pool_pages</li> </ul> |
 | **mysql.buffer_pool.usage** | The number of bytes in the InnoDB buffer pool. | By | Sum(Int) | <ul> <li>buffer_pool_data</li> </ul> |
 | **mysql.commands** | The number of times each type of command has been executed. | 1 | Sum(Int) | <ul> <li>command</li> </ul> |
+| **mysql.connection.errors** | Errors that occur during the client connection process. | 1 | Sum(Int) | <ul> <li>connection_error</li> </ul> |
 | **mysql.double_writes** | The number of writes to the InnoDB doublewrite buffer. | 1 | Sum(Int) | <ul> <li>double_writes</li> </ul> |
 | **mysql.handlers** | The number of requests to various MySQL handlers. | 1 | Sum(Int) | <ul> <li>handler</li> </ul> |
 | **mysql.index.io.wait.count** | The total count of I/O wait events for an index. | 1 | Sum(Int) | <ul> <li>io_waits_operations</li> <li>table_name</li> <li>schema</li> <li>index_name</li> </ul> |
@@ -54,6 +55,7 @@ metrics:
 | buffer_pool_operations (operation) | The buffer pool operations types. | read_ahead_rnd, read_ahead, read_ahead_evicted, read_requests, reads, wait_free, write_requests |
 | buffer_pool_pages (kind) | The buffer pool pages types. | data, free, misc |
 | command (command) | The command types. | execute, close, fetch, prepare, reset, send_long_data |
+| connection_error (error) | The connection error type. | accept, internal, max_connections, peer_address, select, tcpwrap |
 | double_writes (kind) | The doublewrite types. | pages_written, writes |
 | handler (kind) | The handler types. | commit, delete, discover, external_lock, mrr_init, prepare, read_first, read_key, read_last, read_next, read_prev, read_rnd, read_rnd_next, rollback, savepoint, savepoint_rollback, update, write |
 | index_name (index) | The name of the index. |  |

receiver/mysqlreceiver/metadata.yaml

@@ -22,6 +22,10 @@ attributes:
     value: command
     description: The command types.
     enum: [execute, close, fetch, prepare, reset, send_long_data]
+  connection_error:
+    value: error
+    description: The connection error type.
+    enum: [accept, internal, max_connections, peer_address, select, tcpwrap]
   handler:
     value: kind
     description: The handler types.
@@ -283,6 +287,16 @@ metrics:
       monotonic: false
       aggregation: cumulative
     attributes: [threads]
+  mysql.connection.errors:
+    enabled: true
+    description: Errors that occur during the client connection process.
+    unit: 1
+    sum:
+      value_type: int
+      input_type: string
+      monotonic: true
+      aggregation: cumulative
+    attributes: [connection_error]
   mysql.tmp_resources:
     enabled: true
     description: The number of created temporary resources.

receiver/mysqlreceiver/scraper.go

@@ -158,6 +158,26 @@ func (m *mySQLScraper) scrapeGlobalStats(now pcommon.Timestamp, errs *scrapererr
 			addPartialIfError(errs, m.mb.RecordMysqlBufferPoolOperationsDataPoint(now, v,
 				metadata.AttributeBufferPoolOperationsWriteRequests))
 
+		// connection.errors
+		case "Connection_errors_accept":
+			addPartialIfError(errs, m.mb.RecordMysqlConnectionErrorsDataPoint(now, v,
+				metadata.AttributeConnectionErrorAccept))
+		case "Connection_errors_internal":
+			addPartialIfError(errs, m.mb.RecordMysqlConnectionErrorsDataPoint(now, v,
+				metadata.AttributeConnectionErrorInternal))
+		case "Connection_errors_max_connections":
+			addPartialIfError(errs, m.mb.RecordMysqlConnectionErrorsDataPoint(now, v,
+				metadata.AttributeConnectionErrorMaxConnections))
+		case "Connection_errors_peer_address":
+			addPartialIfError(errs, m.mb.RecordMysqlConnectionErrorsDataPoint(now, v,
+				metadata.AttributeConnectionErrorPeerAddress))
+		case "Connection_errors_select":
+			addPartialIfError(errs, m.mb.RecordMysqlConnectionErrorsDataPoint(now, v,
+				metadata.AttributeConnectionErrorSelect))
+		case "Connection_errors_tcpwrap":
+			addPartialIfError(errs, m.mb.RecordMysqlConnectionErrorsDataPoint(now, v,
+				metadata.AttributeConnectionErrorTcpwrap))
+
 		// commands
 		case "Com_stmt_execute":
 			addPartialIfError(errs, m.mb.RecordMysqlCommandsDataPoint(now, v, metadata.AttributeCommandExecute))

receiver/mysqlreceiver/testdata/scraper/expected.json

@@ -351,6 +351,95 @@
                      },
                      "unit": "1"
                   },
+                  {
+                     "description": "Errors that occur during the client connection process.",
+                     "name": "mysql.connection.errors",
+                     "sum": {
+                        "aggregationTemporality": "AGGREGATION_TEMPORALITY_CUMULATIVE",
+                        "dataPoints": [
+                           {
+                              "asInt": "182",
+                              "attributes": [
+                                 {
+                                    "key": "error",
+                                    "value": {
+                                       "stringValue": "accept"
+                                    }
+                                 }
+                              ],
+                              "startTimeUnixNano": "1644862687825728000",
+                              "timeUnixNano": "1644862687825772000"
+                           },
+                           {
+                              "asInt": "183",
+                              "attributes": [
+                                 {
+                                    "key": "error",
+                                    "value": {
+                                       "stringValue": "internal"
+                                    }
+                                 }
+                              ],
+                              "startTimeUnixNano": "1644862687825728000",
+                              "timeUnixNano": "1644862687825772000"
+                           },
+                           {
+                              "asInt": "184",
+                              "attributes": [
+                                 {
+                                    "key": "error",
+                                    "value": {
+                                       "stringValue": "max_connections"
+                                    }
+                                 }
+                              ],
+                              "startTimeUnixNano": "1644862687825728000",
+                              "timeUnixNano": "1644862687825772000"
+                           },
+                           {
+                              "asInt": "185",
+                              "attributes": [
+                                 {
+                                    "key": "error",
+                                    "value": {
+                                       "stringValue": "peer_address"
+                                    }
+                                 }
+                              ],
+                              "startTimeUnixNano": "1644862687825728000",
+                              "timeUnixNano": "1644862687825772000"
+                           },
+                           {
+                              "asInt": "186",
+                              "attributes": [
+                                 {
+                                    "key": "error",
+                                    "value": {
+                                       "stringValue": "select"
+                                    }
+                                 }
+                              ],
+                              "startTimeUnixNano": "1644862687825728000",
+                              "timeUnixNano": "1644862687825772000"
+                           },
+                           {
+                              "asInt": "187",
+                              "attributes": [
+                                 {
+                                    "key": "error",
+                                    "value": {
+                                       "stringValue": "tcpwrap"
+                                    }
+                                 }
+                              ],
+                              "startTimeUnixNano": "1644862687825728000",
+                              "timeUnixNano": "1644862687825772000"
+                           }
+                        ],
+                        "isMonotonic": true
+                     },
+                     "unit": "1"
+                  },
                   {
                      "description": "The number of writes to the InnoDB doublewrite buffer.",
                      "name": "mysql.double_writes",