From fe0707faaaa584b628d7300d213aa77064f64819 Mon Sep 17 00:00:00 2001 From: Amit Kapila Date: Wed, 14 Oct 2020 15:42:23 +0530 Subject: [PATCH v5] Execute invalidation messages for each XLOG_XACT_INVALIDATIONS message during logical decoding. Prior to commit c55040ccd0 we have no way of knowing the invalidations before commit. So, while decoding we use to execute all the invalidations at each command end as we had no way of knowing which invalidations happened before that command. Due to this, transactions involving large amounts of DDLs use to take more time and also lead to high CPU usage. But now we know specific invalidations at each command end so we execute only required invalidations. It has been observed that decoding of a transaction containing truncation of a table with 1000 partitions would be finished in 1s whereas before this patch it used to take 4-5 minutes. Author: Dilip Kumar Reviewed-by: Amit Kapila and Keisuke Kuroda Discussion: https://postgr.es/m/CANDwggKYveEtXjXjqHA6RL3AKSHMsQyfRY6bK+NqhAWJyw8psQ@mail.gmail.com --- src/backend/replication/logical/reorderbuffer.c | 103 +++++++++++++++++++----- src/include/replication/reorderbuffer.h | 12 ++- 2 files changed, 92 insertions(+), 23 deletions(-) diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c index 4cb27f2..7a8bf76 100644 --- a/src/backend/replication/logical/reorderbuffer.c +++ b/src/backend/replication/logical/reorderbuffer.c @@ -235,7 +235,7 @@ static void ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn, static ReorderBufferChange *ReorderBufferIterTXNNext(ReorderBuffer *rb, ReorderBufferIterTXNState *state); static void ReorderBufferIterTXNFinish(ReorderBuffer *rb, ReorderBufferIterTXNState *state); -static void ReorderBufferExecuteInvalidations(ReorderBuffer *rb, ReorderBufferTXN *txn); +static void ReorderBufferExecuteInvalidations(uint32 nmsgs, SharedInvalidationMessage *msgs); /* * --------------------------------------- @@ -486,6 +486,11 @@ ReorderBufferReturnChange(ReorderBuffer *rb, ReorderBufferChange *change, pfree(change->data.msg.message); change->data.msg.message = NULL; break; + case REORDER_BUFFER_CHANGE_INVALIDATION: + if (change->data.inval.invalidations) + pfree(change->data.inval.invalidations); + change->data.inval.invalidations = NULL; + break; case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT: if (change->data.snapshot) { @@ -2194,6 +2199,13 @@ ReorderBufferProcessTXN(ReorderBuffer *rb, ReorderBufferTXN *txn, ReorderBufferApplyMessage(rb, txn, change, streaming); break; + case REORDER_BUFFER_CHANGE_INVALIDATION: + /* Execute the invalidation messages locally */ + ReorderBufferExecuteInvalidations( + change->data.inval.ninvalidations, + change->data.inval.invalidations); + break; + case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT: /* get rid of the old */ TeardownHistoricSnapshot(false); @@ -2244,13 +2256,6 @@ ReorderBufferProcessTXN(ReorderBuffer *rb, ReorderBufferTXN *txn, TeardownHistoricSnapshot(false); SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash); - - /* - * Every time the CommandId is incremented, we could - * see new catalog contents, so execute all - * invalidations. - */ - ReorderBufferExecuteInvalidations(rb, txn); } break; @@ -2317,7 +2322,7 @@ ReorderBufferProcessTXN(ReorderBuffer *rb, ReorderBufferTXN *txn, AbortCurrentTransaction(); /* make sure there's no cache pollution */ - ReorderBufferExecuteInvalidations(rb, txn); + ReorderBufferExecuteInvalidations(txn->ninvalidations, txn->invalidations); if (using_subtxn) RollbackAndReleaseCurrentSubTransaction(); @@ -2356,7 +2361,8 @@ ReorderBufferProcessTXN(ReorderBuffer *rb, ReorderBufferTXN *txn, AbortCurrentTransaction(); /* make sure there's no cache pollution */ - ReorderBufferExecuteInvalidations(rb, txn); + ReorderBufferExecuteInvalidations(txn->ninvalidations, + txn->invalidations); if (using_subtxn) RollbackAndReleaseCurrentSubTransaction(); @@ -2813,10 +2819,13 @@ ReorderBufferAddNewTupleCids(ReorderBuffer *rb, TransactionId xid, * Setup the invalidation of the toplevel transaction. * * This needs to be called for each XLOG_XACT_INVALIDATIONS message and - * accumulates all the invalidation messages in the toplevel transaction. - * This is required because in some cases where we skip processing the - * transaction (see ReorderBufferForget), we need to execute all the - * invalidations together. + * accumulates all the invalidation messages in the toplevel transaction as + * well as in the form of change in reorder buffer. We require to record it in + * form of the change so that we can execute only the required invalidations + * instead of executing all the invalidations on each CommandId increment. We + * also need to accumulate these in the toplevel transaction because in some + * cases we skip processing the transaction (see ReorderBufferForget), we need + * to execute all the invalidations together. */ void ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, @@ -2824,12 +2833,16 @@ ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, SharedInvalidationMessage *msgs) { ReorderBufferTXN *txn; + MemoryContext oldcontext; + ReorderBufferChange *change; txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true); + oldcontext = MemoryContextSwitchTo(rb->context); + /* - * We collect all the invalidations under the top transaction so that we - * can execute them all together. + * Collect all the invalidations under the top transaction so that we can + * execute them all together. See comment atop this function */ if (txn->toptxn) txn = txn->toptxn; @@ -2841,8 +2854,7 @@ ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, { txn->ninvalidations = nmsgs; txn->invalidations = (SharedInvalidationMessage *) - MemoryContextAlloc(rb->context, - sizeof(SharedInvalidationMessage) * nmsgs); + palloc(sizeof(SharedInvalidationMessage) * nmsgs); memcpy(txn->invalidations, msgs, sizeof(SharedInvalidationMessage) * nmsgs); } @@ -2856,6 +2868,18 @@ ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, nmsgs * sizeof(SharedInvalidationMessage)); txn->ninvalidations += nmsgs; } + + change = ReorderBufferGetChange(rb); + change->action = REORDER_BUFFER_CHANGE_INVALIDATION; + change->data.inval.ninvalidations = nmsgs; + change->data.inval.invalidations = (SharedInvalidationMessage *) + palloc(sizeof(SharedInvalidationMessage) * nmsgs); + memcpy(change->data.inval.invalidations, msgs, + sizeof(SharedInvalidationMessage) * nmsgs); + + ReorderBufferQueueChange(rb, xid, lsn, change, false); + + MemoryContextSwitchTo(oldcontext); } /* @@ -2863,12 +2887,12 @@ ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, * in the changestream but we don't know which those are. */ static void -ReorderBufferExecuteInvalidations(ReorderBuffer *rb, ReorderBufferTXN *txn) +ReorderBufferExecuteInvalidations(uint32 nmsgs, SharedInvalidationMessage *msgs) { int i; - for (i = 0; i < txn->ninvalidations; i++) - LocalExecuteInvalidationMessage(&txn->invalidations[i]); + for (i = 0; i < nmsgs; i++) + LocalExecuteInvalidationMessage(&msgs[i]); } /* @@ -3303,6 +3327,24 @@ ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn, break; } + case REORDER_BUFFER_CHANGE_INVALIDATION: + { + char *data; + Size inval_size = sizeof(SharedInvalidationMessage) * + change->data.inval.ninvalidations; + + sz += inval_size; + + ReorderBufferSerializeReserve(rb, sz); + data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange); + + /* might have been reallocated above */ + ondisk = (ReorderBufferDiskChange *) rb->outbuf; + memcpy(data, change->data.inval.invalidations, inval_size); + data += inval_size; + + break; + } case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT: { Snapshot snap; @@ -3578,6 +3620,12 @@ ReorderBufferChangeSize(ReorderBufferChange *change) break; } + case REORDER_BUFFER_CHANGE_INVALIDATION: + { + sz += sizeof(SharedInvalidationMessage) * + change->data.inval.ninvalidations; + break; + } case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT: { Snapshot snap; @@ -3846,6 +3894,19 @@ ReorderBufferRestoreChange(ReorderBuffer *rb, ReorderBufferTXN *txn, break; } + case REORDER_BUFFER_CHANGE_INVALIDATION: + { + Size inval_size = sizeof(SharedInvalidationMessage) * + change->data.inval.ninvalidations; + + change->data.inval.invalidations = + MemoryContextAlloc(rb->context, inval_size); + + /* read the message */ + memcpy(change->data.inval.invalidations, data, inval_size); + + break; + } case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT: { Snapshot oldsnap; diff --git a/src/include/replication/reorderbuffer.h b/src/include/replication/reorderbuffer.h index 0cc3aeb..1c77819 100644 --- a/src/include/replication/reorderbuffer.h +++ b/src/include/replication/reorderbuffer.h @@ -57,6 +57,7 @@ enum ReorderBufferChangeType REORDER_BUFFER_CHANGE_UPDATE, REORDER_BUFFER_CHANGE_DELETE, REORDER_BUFFER_CHANGE_MESSAGE, + REORDER_BUFFER_CHANGE_INVALIDATION, REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT, REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID, REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID, @@ -149,6 +150,13 @@ typedef struct ReorderBufferChange CommandId cmax; CommandId combocid; } tuplecid; + + /* Invalidation. */ + struct + { + uint32 ninvalidations; /* Number of messages */ + SharedInvalidationMessage *invalidations; /* invalidation message */ + } inval; } data; /* @@ -313,8 +321,8 @@ typedef struct ReorderBufferTXN uint64 nentries_mem; /* - * List of ReorderBufferChange structs, including new Snapshots and new - * CommandIds + * List of ReorderBufferChange structs, including new Snapshots, new + * CommandIds and command invalidation messages. */ dlist_head changes; -- 1.8.3.1