!1431 修改支持配置延迟进入最大可用模式需求的代码逻辑和相关问题

Merge pull request !1431 from cchen676/new_master

src/bin/gs_guc/cluster_guc.cpp

@@ -2682,6 +2682,10 @@ static void readPopenOutputParallel(const char* cmd, bool if_for_all_instance)
                 }
                 curr_cxt->readbuf[0] = '\0';
                 curr_cxt->cur_buf_loc = 0;
+                endsp = strstr(result, "WARNING");
+                if (NULL != endsp) {
+                    (void)write_stderr("%s", result);
+                }
                 endsp = strstr(result, "Success to perform gs_guc");
                 if (NULL != endsp) {
                     successNumber++;

src/gausskernel/storage/replication/syncrep.cpp

@@ -101,6 +101,7 @@ static bool SyncPaxosQueueIsOrderedByLSN(void);
 static List *SyncRepGetSyncStandbysPriority(bool *am_sync, List** catchup_standbys = NULL);
 static List *SyncRepGetSyncStandbysQuorum(bool *am_sync, List** catchup_standbys = NULL);
 static int cmp_lsn(const void *a, const void *b);
+static bool DelayIntoMostAvaSync(bool checkSyncNum, int curSyncNum = 0);
 
 #define CATCHUP_XLOG_DIFF(ptr1, ptr2, amount) \
     XLogRecPtrIsInvalid(ptr1) ? false : (XLByteDifference(ptr2, ptr1) < amount)
@@ -155,9 +156,6 @@ void SyncRepWaitForLSN(XLogRecPtr XactCommitLSN, bool enableHandleCancel)
     char *new_status = NULL;
     const char *old_status = NULL;
     int mode = u_sess->attr.attr_storage.sync_rep_wait_mode;
-    TimestampTz now_time;
-    TimestampTz now_time_dynamical;
-    bool sync_master_standalone_window = false;
 
     /*
      * Fast exit if user has not requested sync replication, or there are no
@@ -185,21 +183,10 @@ void SyncRepWaitForLSN(XLogRecPtr XactCommitLSN, bool enableHandleCancel)
      * condition but we'll be fetching that cache line anyway so its likely to
      * be a low cost check. We don't wait for sync rep if no sync standbys alive
      */
-    now_time = GetCurrentTimestamp();
-    long diff_sec;
-    int diff_microsec;
-
-    if (t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone) {
-        TimestampDifference(t_thrd.walsender_cxt.WalSndCtl->last_sync_master_standalone_time, now_time, &diff_sec,
-                            &diff_microsec);
-        if (diff_sec >= (long)u_sess->attr.attr_storage.keep_sync_window) {
-            sync_master_standalone_window = true;
-        }
-    }
-
     if (!t_thrd.walsender_cxt.WalSndCtl->sync_standbys_defined ||
         XLByteLE(XactCommitLSN, t_thrd.walsender_cxt.WalSndCtl->lsn[mode]) ||
-        (sync_master_standalone_window && !IS_SHARED_STORAGE_MODE) ||
+        (t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone && !IS_SHARED_STORAGE_MODE &&
+         !DelayIntoMostAvaSync(false)) ||
         !SynRepWaitCatchup(XactCommitLSN)) {
         LWLockRelease(SyncRepLock);
         RESUME_INTERRUPTS();
@@ -263,8 +250,9 @@ void SyncRepWaitForLSN(XLogRecPtr XactCommitLSN, bool enableHandleCancel)
          * walsender changes the state to SYNC_REP_WAIT_COMPLETE, it will never
          * update it again, so we can't be seeing a stale value in that case.
          */
-        if (t_thrd.proc->syncRepState == SYNC_REP_WAIT_COMPLETE)
+        if (t_thrd.proc->syncRepState == SYNC_REP_WAIT_COMPLETE && !DelayIntoMostAvaSync(true)) {
             break;
+        }
 
         /*
          * If a wait for synchronous replication is pending, we can neither
@@ -327,18 +315,9 @@ void SyncRepWaitForLSN(XLogRecPtr XactCommitLSN, bool enableHandleCancel)
         /*
          * If we  modify the syncmode dynamically, we'll stop wait
          */
-        now_time_dynamical = GetCurrentTimestamp();
+        if ((t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone && !IS_SHARED_STORAGE_MODE &&
-        long diff_sec_dynamical;
+             !DelayIntoMostAvaSync(false)) ||
-        int diff_microsec_dynamical;
+            u_sess->attr.attr_storage.guc_synchronous_commit <= SYNCHRONOUS_COMMIT_LOCAL_FLUSH) {
-        if (t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone) {
-            TimestampDifference(t_thrd.walsender_cxt.WalSndCtl->last_sync_master_standalone_time, now_time_dynamical,
-                                &diff_sec_dynamical, &diff_microsec_dynamical);
-        }
-
-        if ((sync_master_standalone_window && !IS_SHARED_STORAGE_MODE) ||
-            u_sess->attr.attr_storage.guc_synchronous_commit <= SYNCHRONOUS_COMMIT_LOCAL_FLUSH ||
-            (t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone &&
-             diff_sec_dynamical >= (long)u_sess->attr.attr_storage.keep_sync_window)) {
             ereport(WARNING,
                     (errmsg("canceling wait for synchronous replication due to syncmaster standalone."),
                      errdetail("The transaction has already committed locally, but might not have been replicated to "
@@ -627,6 +606,55 @@ void SyncRepReleaseWaiters(void)
                     numapply, (uint32)(replayPtr >> 32), (uint32)replayPtr)));
 }
 
+/*
+ * Check whether to delay the time of entering most_available_sync mode.
+ *
+ * Return false if keep_sync_window is not set, or most_available_sync
+ * is not set, or current time is not in the time range since the time
+ * when the number of sync standby is not qualified.
+ * Otherwise it's set to true.
+ */
+static bool DelayIntoMostAvaSync(bool checkSyncNum, int curSyncNum)
+{
+    bool result = false;
+
+    if (!t_thrd.walsender_cxt.WalSndCtl->most_available_sync || !u_sess->attr.attr_storage.keep_sync_window) {
+        return result;
+    }
+
+    if (checkSyncNum) {
+        List *sync_standbys = NIL;
+        bool am_sync = false;
+        sync_standbys = SyncRepGetSyncStandbys(&am_sync);
+        curSyncNum = list_length(sync_standbys);
+    }
+
+    if (curSyncNum == t_thrd.syncrep_cxt.SyncRepConfig->num_sync) {
+        if (t_thrd.walsender_cxt.WalSndCtl->keep_sync_window_start != 0) {
+            t_thrd.walsender_cxt.WalSndCtl->keep_sync_window_start = 0;
+            t_thrd.walsender_cxt.WalSndCtl->out_keep_sync_window = false;
+        }
+    } else if (t_thrd.walsender_cxt.WalSndCtl->keep_sync_window_start == 0) {
+        t_thrd.walsender_cxt.WalSndCtl->keep_sync_window_start = GetCurrentTimestamp();
+        result = true;
+    } else if (!t_thrd.walsender_cxt.WalSndCtl->out_keep_sync_window) {
+        TimestampTz now_time = 0;
+        long diff_sec = 0;
+        int diff_microsec = 0;
+        now_time = GetCurrentTimestamp();
+        TimestampDifference(t_thrd.walsender_cxt.WalSndCtl->keep_sync_window_start, now_time, &diff_sec,
+                            &diff_microsec);
+        if (diff_sec < (long)u_sess->attr.attr_storage.keep_sync_window) {
+            result = true;
+            ereport(DEBUG1, (errmsg("Delay to entering most_available_sync mode, %ld seconds passed.", diff_sec)));
+        } else {
+            t_thrd.walsender_cxt.WalSndCtl->out_keep_sync_window = true;
+        }
+    }
+
+    return result;
+}
+
 /*
  * Calculate the synced Receive, Write, Flush and Apply positions among sync standbys.
  *
@@ -655,9 +683,10 @@ bool SyncRepGetSyncRecPtr(XLogRecPtr *receivePtr, XLogRecPtr *writePtr, XLogRecP
      * but in a particular scenario, when most_available_sync is true, primary only wait the alive sync standbys
      * if list_length(sync_standbys) doesn't satisfy t_thrd.syncrep_cxt.SyncRepConfig->num_sync.
      */
+    int cur_num_sync_standbys = list_length(sync_standbys);
     if ((!(*am_sync) && check_am_sync) || t_thrd.syncrep_cxt.SyncRepConfig == NULL ||
-        (!t_thrd.walsender_cxt.WalSndCtl->most_available_sync &&
+        ((!t_thrd.walsender_cxt.WalSndCtl->most_available_sync || DelayIntoMostAvaSync(false, cur_num_sync_standbys)) &&
-        list_length(sync_standbys) < t_thrd.syncrep_cxt.SyncRepConfig->num_sync)) {
+         cur_num_sync_standbys < t_thrd.syncrep_cxt.SyncRepConfig->num_sync)) {
         list_free(sync_standbys);
         return false;
     }
@@ -1404,8 +1433,6 @@ void SyncRepCheckSyncStandbyAlive(void)
         ereport(LOG, (errmsg("synchronous master is now standalone")));
 
         t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone = true;
-        t_thrd.walsender_cxt.WalSndCtl->last_sync_master_standalone_time = GetCurrentTimestamp();
-
         /*
          * If there is any waiting sender, then wake-up them as
          * master has switched to standalone mode

src/gausskernel/storage/replication/walsender.cpp

@@ -4620,7 +4620,8 @@ void WalSndShmemInit(void)
         }
         t_thrd.walsender_cxt.WalSndCtl->most_available_sync = false;
         t_thrd.walsender_cxt.WalSndCtl->sync_master_standalone = false;
-        t_thrd.walsender_cxt.WalSndCtl->last_sync_master_standalone_time = 0;
+        t_thrd.walsender_cxt.WalSndCtl->keep_sync_window_start = 0;
+        t_thrd.walsender_cxt.WalSndCtl->out_keep_sync_window = false;
         t_thrd.walsender_cxt.WalSndCtl->demotion = NoDemote;
         SpinLockInit(&t_thrd.walsender_cxt.WalSndCtl->mutex);
     }

src/include/replication/walsender_private.h

@@ -183,8 +183,9 @@ typedef struct WalSndCtlData {
      * mode.
      */
     bool sync_master_standalone;
-    TimestampTz last_sync_master_standalone_time;
+    TimestampTz keep_sync_window_start;
-
+    bool out_keep_sync_window;
+    
     /*
      * The demotion of postmaster  Also indicates that all the walsenders
      * should reject any demote requests if postmaster is doning domotion.