Use redo field to distinguish shutdown andonine checkpoints

neondatabase · Dec 4, 2024 · 13dd2f1 · 13dd2f1
1 parent 4dbb469
commit 13dd2f1
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Showing 2 changed files with 15 additions and 12 deletions.
diff --git a/pageserver/src/basebackup.rs b/pageserver/src/basebackup.rs
@@ -29,9 +29,7 @@ use crate::tenant::Timeline;
 use pageserver_api::reltag::{RelTag, SlruKind};
 
 use postgres_ffi::pg_constants::{DEFAULTTABLESPACE_OID, GLOBALTABLESPACE_OID};
-use postgres_ffi::pg_constants::{
-    PGDATA_SPECIAL_FILES, PG_HBA, SIZE_OF_XLOG_RECORD_DATA_HEADER_SHORT,
-};
+use postgres_ffi::pg_constants::{PGDATA_SPECIAL_FILES, PG_HBA};
 use postgres_ffi::relfile_utils::{INIT_FORKNUM, MAIN_FORKNUM};
 use postgres_ffi::XLogFileName;
 use postgres_ffi::PG_TLI;
@@ -264,13 +262,8 @@ where
             if let Ok(checkpoint_bytes) = self.timeline.get_checkpoint(self.lsn, self.ctx).await {
                 let checkpoint =
                     CheckPoint::decode(&checkpoint_bytes).context("deserialize checkpoint")?;
-                let checkpoint_end_lsn = calculate_walrecord_end_lsn(
-                    Lsn(checkpoint.redo),
-                    XLOG_SIZE_OF_XLOG_RECORD
-                        + SIZE_OF_XLOG_RECORD_DATA_HEADER_SHORT
-                        + SIZEOF_CHECKPOINT,
-                );
-                checkpoint_end_lsn == self.lsn
+                // We store "redo" field only for shutdown checkpoint
+                checkpoint.redo != 0
             } else {
                 false
             };

diff --git a/pageserver/src/walingest.rs b/pageserver/src/walingest.rs
@@ -1187,8 +1187,18 @@ impl WalIngest {
                 } else {
                     cp.oldestActiveXid = xlog_checkpoint.oldestActiveXid;
                 }
-                cp.redo = xlog_checkpoint.redo;
-
+                //
+                // There is no any field in CheckPoint which allows to distinguish online
+                // and shutdown checkpoint. And we need to know it to detect normal shutdown.
+                // Previously "redo" field was not set at all.
+                // So let's assign this field only for shutdown checkpoint and left it zero
+                // for online checkpoint.
+                //
+                cp.redo = if info == pg_constants::XLOG_CHECKPOINT_SHUTDOWN {
+                    xlog_checkpoint.redo
+                } else {
+                    0
+                };
                 // Write a new checkpoint key-value pair on every checkpoint record, even
                 // if nothing really changed. Not strictly required, but it seems nice to
                 // have some trace of the checkpoint records in the layer files at the same