Adds replacements for postgres-exporter queries

Author: tony-landreth

internal/collector/generated/gte_pg17_metrics.json

@@ -4,6 +4,36 @@
 # https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/-/receiver/sqlqueryreceiver#metrics-queries
 # https://github.com/CrunchyData/pgmonitor/blob/development/sql_exporter/common/crunchy_global_collector.yml
 
+  - sql: >
+      SELECT c.buffers_written
+      FROM pg_catalog.pg_stat_checkpointer c;
+    metrics:
+      - metric_name: ccp_stat_bgwriter_buffers_checkpoint
+        data_type: sum
+        description: Number of buffers written during checkpoints and restartpoints
+        static_attributes:
+          server: "localhost:5432"
+
+  - sql: >
+      SELECT
+          s.writes
+          , s.fsyncs
+      FROM pg_catalog.pg_stat_io s
+      WHERE backend_type = 'background writer';
+    metrics:
+      - metric_name: ccp_stat_bgwriter_buffers_backend
+        value_column: writes
+        data_type: sum
+        description: Number of write operations, each of the size specified in op_bytes.
+        static_attributes:
+          server: "localhost:5432"
+      - metric_name: ccp_stat_bgwriter_buffers_backend_fsync
+        value_column: fsyncs
+        data_type: sum
+        description: Number of fsync calls. These are only tracked in context normal.
+        static_attributes:
+          server: "localhost:5432"
+
   - sql: >
       SELECT
           c.num_timed

internal/collector/generated/lt_pg17_metrics.json

@@ -4,6 +4,36 @@
 # https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/-/receiver/sqlqueryreceiver#metrics-queries
 # https://github.com/CrunchyData/pgmonitor/blob/development/sql_exporter/common/crunchy_global_collector.yml
 
+  - sql: >
+      SELECT c.buffers_checkpoint AS buffers_written
+      FROM pg_catalog.pg_stat_bgwriter c;
+    metrics:
+      - metric_name: ccp_stat_bgwriter_buffers_checkpoint
+        value_column: buffers_written
+        data_type: sum
+        description: Number of buffers written during checkpoints and restartpoints
+        static_attributes:
+          server: "localhost:5432"
+
+  - sql: >
+      SELECT
+          s.buffers_backend AS writes
+          , s.buffers_backend_fsync AS fsyncs
+      FROM pg_catalog.pg_stat_bgwriter s;
+    metrics:
+      - metric_name: ccp_stat_bgwriter_buffers_backend
+        value_column: writes
+        data_type: sum
+        description: Number of write operations, each of the size specified in op_bytes.
+        static_attributes:
+          server: "localhost:5432"
+      - metric_name: ccp_stat_bgwriter_buffers_backend_fsync
+        value_column: fsyncs
+        data_type: sum
+        description: Number of fsync calls. These are only tracked in context normal.
+        static_attributes:
+          server: "localhost:5432"
+
   - sql: >
       SELECT
           c.checkpoints_timed AS num_timed

internal/collector/generated/postgres_5s_metrics.json

@@ -589,6 +589,18 @@
         static_attributes:
           server: "localhost:5432"
 
+  # ccp_replication_lag_size_bytes will return NULL on a replica
+  - sql: >
+      SELECT pg_wal_lsn_diff(sent_lsn, replay_lsn) AS bytes
+          FROM pg_catalog.pg_stat_replication;
+    metrics:
+      - metric_name: ccp_replication_lag_size_bytes
+        value_column: bytes
+        value_type: double
+        description: Time interval in seconds since PostgreSQL database was last restarted.
+        static_attributes:
+          server: "localhost:5432"
+
   - sql: >
       SELECT
          CASE
@@ -600,7 +612,12 @@
          WHEN pg_is_in_recovery() = false THEN 0
          ELSE EXTRACT (EPOCH FROM clock_timestamp() - pg_last_xact_replay_timestamp())::INTEGER
          END
-      AS received_time;
+      AS received_time
+      ,  CASE
+         WHEN pg_is_in_recovery() = true THEN 'replica'
+         ELSE 'primary'
+         END
+      AS role;
     metrics:
       - metric_name: ccp_replication_lag_received_time 
         value_column: received_time
@@ -609,6 +626,7 @@
           Length of time since the last WAL file was received and replayed on replica.
           Always increases, possibly causing false positives if the primary stops writing.
           Monitors for replicas that stop receiving WAL all together.
+        attribute_columns: ["role"]
         static_attributes:
           server: "localhost:5432"
       - metric_name: ccp_replication_lag_replay_time 
@@ -619,6 +637,7 @@
           Returns zero if last WAL received equals last WAL replayed. Avoids
           false positives when primary stops writing. Monitors for replicas that
           cannot keep up with primary WAL generation.
+        attribute_columns: ["role"]
         static_attributes:
           server: "localhost:5432"
 
@@ -645,6 +664,7 @@
           server: "localhost:5432"
       - metric_name: ccp_stat_bgwriter_buffers_clean  
         value_column: buffers_clean
+        data_type: sum
         description: Number of buffers written by the background writer
         static_attributes:
           server: "localhost:5432"