wal_decoder: add rate limited log for unexpected rm ids

libs/postgres_ffi/src/pg_constants.rs

@@ -170,6 +170,7 @@ pub const RM_RELMAP_ID: u8 = 7;
 pub const RM_STANDBY_ID: u8 = 8;
 pub const RM_HEAP2_ID: u8 = 9;
 pub const RM_HEAP_ID: u8 = 10;
+pub const RM_BTREE_ID: u8 = 11;
 pub const RM_REPLORIGIN_ID: u8 = 19;
 pub const RM_LOGICALMSG_ID: u8 = 21;
 

libs/wal_decoder/Cargo.toml

@@ -10,6 +10,7 @@ testing = []
 [dependencies]
 anyhow.workspace = true
 bytes.workspace = true
+once_cell.workspace = true
 pageserver_api.workspace = true
 postgres_ffi.workspace = true
 serde.workspace = true

libs/wal_decoder/src/decoder.rs

@@ -169,9 +169,29 @@ impl MetadataRecord {
             }
             pg_constants::RM_STANDBY_ID => Self::decode_standby_record(&mut buf, decoded),
             pg_constants::RM_REPLORIGIN_ID => Self::decode_replorigin_record(&mut buf, decoded),
-            _unexpected => {
+            pg_constants::RM_BTREE_ID => {
+                // No special handling required for these record types.
+                // We just ingest the blocks that come with it.
+                Ok(None)
+            }
+            unexpected => {
                 // TODO: consider failing here instead of blindly doing something without
                 // understanding the protocol
+                use once_cell::sync::Lazy;
+                use std::sync::Mutex;
+                use std::time::Duration;
+                use utils::rate_limit::RateLimit;
+
+                static LOGGED: Lazy<Mutex<RateLimit>> =
+                    Lazy::new(|| Mutex::new(RateLimit::new(Duration::from_secs(10))));
+                let mut rate_limit = LOGGED.try_lock().unwrap();
+                rate_limit.call(|| {
+                    tracing::warn!(
+                        "Unexpected resource manager id in PG WAL record at LSN {}: {}",
+                        lsn,
+                        unexpected
+                    );
+                });
                 Ok(None)
             }
         }