enh: persist wal at the beginning of vnodeCommit

include/libs/wal/wal.h

@@ -43,7 +43,7 @@ extern "C" {
 #define WAL_FILE_LEN         (WAL_PATH_LEN + 32)
 #define WAL_MAGIC            0xFAFBFCFDF4F3F2F1ULL
 #define WAL_SCAN_BUF_SIZE    (1024 * 1024 * 3)
-#define WAL_RECOV_SIZE_LIMIT (100 * WAL_SCAN_BUF_SIZE)
+#define WAL_RECOV_SIZE_LIMIT (200 * WAL_SCAN_BUF_SIZE)
 
 typedef enum {
   TAOS_WAL_WRITE = 1,
@@ -159,6 +159,7 @@ void    walCleanUp();
 // handle open and ctl
 SWal   *walOpen(const char *path, SWalCfg *pCfg);
 int32_t walAlter(SWal *, SWalCfg *pCfg);
+int32_t walPersist(SWal *);
 void    walClose(SWal *);
 
 // write interfaces

source/dnode/vnode/src/vnd/vnodeCommit.c

@@ -212,6 +212,12 @@ int vnodeCommit(SVnode *pVnode) {
   vInfo("vgId:%d, start to commit, commit ID:%" PRId64 " version:%" PRId64, TD_VID(pVnode), pVnode->state.commitID,
         pVnode->state.applied);
 
+  // persist wal before starting
+  if (walPersist(pVnode->pWal) < 0) {
+    vError("vgId:%d, failed to persist wal since %s", TD_VID(pVnode), terrstr());
+    return -1;
+  }
+
   pVnode->state.commitTerm = pVnode->state.applyTerm;
 
   // save info

source/libs/wal/src/walMgmt.c

@@ -187,6 +187,13 @@ int32_t walAlter(SWal *pWal, SWalCfg *pCfg) {
   return 0;
 }
 
+int32_t walPersist(SWal *pWal) {
+  taosThreadMutexLock(&pWal->mutex);
+  int32_t ret = walSaveMeta(pWal);
+  taosThreadMutexUnlock(&pWal->mutex);
+  return ret;
+}
+
 void walClose(SWal *pWal) {
   taosThreadMutexLock(&pWal->mutex);
   (void)walSaveMeta(pWal);