[-] fix replication slots metrics for replica instances (#768)

* Fix of replication slots metrics when it's executed on the replica instance and pg_current_wal_lsn execution is not allowed * Update pgwatch2/metrics/replication_slots/10/metric_master.sql --------- Co-authored-by: Pavlo Golub <pavlo.golub@gmail.com>
cybertec-postgresql · Apr 24, 2024 · 35fbf79 · 35fbf79
1 parent 4387798
commit 35fbf79
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/pgwatch2/metrics/replication_slots/10/metric_master.sql b/pgwatch2/metrics/replication_slots/10/metric_master.sql
@@ -4,8 +4,10 @@ select /* pgwatch2_generated */
   coalesce(plugin, 'physical')::text as tag_plugin,
   active,
   case when active then 0 else 1 end as non_active_int,
-  pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)::int8 as restart_lsn_lag_b,
-  pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn)::int8 as confirmed_flush_lsn_lag_b,
+  case when not pg_is_in_recovery() then pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)::int8
+  else pg_wal_lsn_diff(pg_last_wal_replay_lsn(), restart_lsn)::int8 end as restart_lsn_lag_b,
+  case when not pg_is_in_recovery() then pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn)::int8
+  else pg_wal_lsn_diff(pg_last_wal_replay_lsn(), confirmed_flush_lsn)::int8 end as confirmed_flush_lsn_lag_b,
   greatest(age(xmin), age(catalog_xmin))::int8 as xmin_age_tx
 from
   pg_replication_slots;
diff --git a/pgwatch2/sql/config_store/metric_definitions.sql b/pgwatch2/sql/config_store/metric_definitions.sql
@@ -6929,8 +6929,10 @@ select
   coalesce(plugin, 'physical')::text as plugin,
   active,
   case when active then 0 else 1 end as non_active_int,
-  pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)::int8 as restart_lsn_lag_b,
-  pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn)::int8 as confirmed_flush_lsn_lag_b,
+  case when not pg_is_in_recovery() then pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)::int8
+  else pg_wal_lsn_diff(pg_last_wal_replay_lsn(), restart_lsn)::int8 end as restart_lsn_lag_b,
+  case when not pg_is_in_recovery() then pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn)::int8
+  else pg_wal_lsn_diff(pg_last_wal_replay_lsn(), confirmed_flush_lsn)::int8 end as confirmed_flush_lsn_lag_b,
   greatest(age(xmin), age(catalog_xmin))::int8 as xmin_age_tx
 from
   pg_replication_slots;