Return sentinel for non-existant record

markhannum · markhannum · commit 54c59517fbda · 2025-12-04T07:34:24.000-05:00
Signed-off-by: Mark Hannum &lt;mhannum72@gmail.com&gt;
diff --git a/db/db_tunables.h b/db/db_tunables.h
@@ -1808,7 +1808,7 @@ REGISTER_TUNABLE("match_on_ckp", "Allow rep_verify_match on ckp records.  (Defau
                  &gbl_match_on_ckp, EXPERIMENTAL | INTERNAL, NULL, NULL, NULL, NULL);
 
 /* physical replication */
-REGISTER_TUNABLE("blocking_physrep", "Physical replicant blocks on select. (Default: off)", TUNABLE_BOOLEAN,
+REGISTER_TUNABLE("blocking_physrep", "Physical replicant blocks on select. (Default: on)", TUNABLE_BOOLEAN,
                  &gbl_blocking_physrep, 0, NULL, NULL, NULL, NULL);
 REGISTER_TUNABLE("tranlog_default_timeout", "Default timeout for tranlog queries.  (Default: 30)", TUNABLE_INTEGER,
                  &gbl_tranlog_default_timeout, 0, NULL, NULL, NULL, NULL);
@@ -1885,7 +1885,7 @@ REGISTER_TUNABLE("physrep_ignore_queues", "Don't replicate queues.", TUNABLE_BOO
                  READONLY, NULL, NULL, NULL, NULL);
 REGISTER_TUNABLE("physrep_max_rollback", "Maximum logs physrep can rollback. (Default: 0)", TUNABLE_INTEGER,
                  &gbl_physrep_max_rollback, 0, NULL, NULL, NULL, NULL);
-REGISTER_TUNABLE("physrep_pollms", "Physical replicant poll interval in milliseconds. (Default: 200)", TUNABLE_INTEGER,
+REGISTER_TUNABLE("physrep_pollms", "Physical replicant poll interval in milliseconds. (Default: 0)", TUNABLE_INTEGER,
                  &gbl_physrep_pollms, 0, NULL, NULL, NULL, NULL);
 
 /* reversql-sql */
diff --git a/db/phys_rep.c b/db/phys_rep.c
@@ -673,6 +673,8 @@ int is_valid_lsn(unsigned int file, unsigned int offset)
            offset == get_next_offset(thedb->bdb_env->dbenv, info);
 }
 
+extern __thread int physrep_out_of_order;
+
 static LOG_INFO handle_record(cdb2_hndl_tp *repl_db, LOG_INFO prev_info)
 {
     /* vars for 1 record */
@@ -693,6 +695,13 @@ static LOG_INFO handle_record(cdb2_hndl_tp *repl_db, LOG_INFO prev_info)
         physrep_logmsg(LOGMSG_ERROR, "%s:%d: Could not parse lsn %s\n",
                        __func__, __LINE__, lsn);
     }
+    if (file == -1 && offset == -1) {
+        if (gbl_physrep_debug) {
+            physrep_logmsg(LOGMSG_USER, "%s:%d requested invalid record, force reconnect\n", __func__, __LINE__);
+        }
+        physrep_out_of_order = 1;
+        return prev_info;
+    }
     if (gbl_physrep_debug) {
         physrep_logmsg(LOGMSG_USER, "%s:%d: Processing record (lsn %d:%d)\n",
                        __func__, __LINE__, file, offset);
@@ -1363,7 +1372,6 @@ static int do_wait_for_reverse_conn(cdb2_hndl_tp *repl_metadb) {
        apply physical logs.
 */
 int gbl_physrep_pollms = 0;
-extern __thread int physrep_out_of_order;
 static void *physrep_worker(void *args)
 {
     comdb2_name_thread(__func__);
@@ -1565,10 +1573,8 @@ static void *physrep_worker(void *args)
 
         prev_info = info;
 
-        rc = snprintf(sql_cmd, sql_cmd_len,
-                      "select * from comdb2_transaction_logs('{%u:%u}'%s)",
-                      info.file, info.offset,
-                      (gbl_blocking_physrep ? ", NULL, 1" : ""));
+        rc = snprintf(sql_cmd, sql_cmd_len, "select * from comdb2_transaction_logs('{%u:%u}', NULL%s)", info.file,
+                      info.offset, (gbl_blocking_physrep ? ",9" : ",8"));
         if (rc < 0 || rc >= sql_cmd_len)
             physrep_logmsg(LOGMSG_ERROR, "%s:%d Command buffer is not long enough!\n", __func__, __LINE__);
         if (gbl_physrep_debug)
diff --git a/sqlite/ext/comdb2/tranlog.c b/sqlite/ext/comdb2/tranlog.c
@@ -69,6 +69,7 @@ struct tranlog_cursor {
   int startAppRecGen;
   int starttime;
   int timeout;
+  int invalidRecord;
   DB_LOGC *logc;             /* Log Cursor */
   DBT data;
 };
@@ -154,6 +155,11 @@ static int tranlogNext(sqlite3_vtab_cursor *cur)
   uint32_t durable_gen=0, rc, getflags;
   bdb_state_type *bdb_state = thedb->bdb_env;
 
+  if (pCur->invalidRecord) {
+      pCur->hitLast = 1;
+      return SQLITE_OK;
+  }
+
   if (pCur->notDurable || pCur->hitLast)
       return SQLITE_OK;
 
@@ -252,9 +258,13 @@ static int tranlogNext(sqlite3_vtab_cursor *cur)
       }
        
       if (getflags != DB_NEXT && getflags != DB_PREV) {
-          logmsg(LOGMSG_ERROR, "%s line %d did not expect logc->get to fail with flag: %d."
-                               "got rc %d\n",
-                  __func__, __LINE__, getflags, rc);
+          if (pCur->flags & TRANLOG_FLAGS_SENTINEL) {
+              /* Return sentinel record with LSN {-1:-1} */
+              pCur->curLsn.file = pCur->curLsn.offset = -1;
+              pCur->invalidRecord = 1;
+              pCur->iRowid++;
+              return SQLITE_OK;
+          }
           return SQLITE_INTERNAL;
       }
 
@@ -665,7 +675,9 @@ static int tranlogColumn(
         }
         break;
     case TRANLOG_COLUMN_TXNID:
-        LOGCOPY_32(&txnid, &((char *) pCur->data.data)[4]); 
+        if (pCur->data.data) {
+            LOGCOPY_32(&txnid, &((char *) pCur->data.data)[4]); 
+        }
         sqlite3_result_int64(ctx, txnid);
         break;
     case TRANLOG_COLUMN_UTXNID:
@@ -717,7 +729,11 @@ static int tranlogColumn(
         }
         break;
     case TRANLOG_COLUMN_LOG:
-        sqlite3_result_blob(ctx, pCur->data.data, pCur->data.size, NULL);
+        if (pCur->data.data) {
+            sqlite3_result_blob(ctx, pCur->data.data, pCur->data.size, NULL);
+        } else {
+            sqlite3_result_null(ctx);
+        }
         break;
     case TRANLOG_COLUMN_CHILDUTXNID:
         if (pCur->data.data)
diff --git a/sqlite/ext/comdb2/tranlog.h b/sqlite/ext/comdb2/tranlog.h
@@ -24,6 +24,7 @@ enum {
     TRANLOG_FLAGS_BLOCK             = 0x1,
     TRANLOG_FLAGS_DURABLE           = 0x2,
     TRANLOG_FLAGS_DESCENDING        = 0x4,
+    TRANLOG_FLAGS_SENTINEL          = 0x8,
 };
 
 u_int64_t get_timestamp_from_matchable_record(char *data);
diff --git a/tests/phys_rep_tiered.test/runit b/tests/phys_rep_tiered.test/runit
@@ -1996,6 +1996,16 @@ function verify_alt_metadb_system_table
     fi
 }
 
+# Ask for a non-existent record with and without sentinel flag
+function non_existent_record
+{
+    x=$($CDB2SQL_EXE --tabs $CDB2_OPTIONS $DBNAME default "select lsn from comdb2_transaction_logs('{1:1}', NULL, 8)" 2>/dev/null)
+    [[ "$x" != '{-1:-1}' ]] && cleanFailExit "Expected {-1:-1} for non-existent record with sentinel flag, got $x"
+
+    x=$($CDB2SQL_EXE --tabs $CDB2_OPTIONS $DBNAME default "select lsn from comdb2_transaction_logs('{1:1}', NULL, 0)" 2>/dev/null)
+    [[ -n "$x" ]] && cleanFailExit "Expected no output, got $x, for non-existent record without sentinel flag"
+}
+
 # Halt a clustered physical replicant .. swing the master on that cluster
 # a number of times, then restart the physical replicant .. looking at the 
 # trace, verify that nothing ignores rectype 2, 11, or 10 ..
@@ -2215,6 +2225,11 @@ function run_tests
     check_metadb_memstat
     testcase_finish $testcase
 
+    testcase="non_existent_record"
+    testcase_preamble $testcase
+    non_existent_record
+    testcase_finish $testcase
+
     testcase="verify_non_ignored_reptype"
     testcase_preamble $testcase
     verify_non_ignored_reptype
diff --git a/tests/tunables.test/t00_all_tunables.expected b/tests/tunables.test/t00_all_tunables.expected
@@ -82,7 +82,7 @@
 (name='blobmem_sz_thresh_kb', description='Sets the threshold (in KB) above which blobs are allocated by the blob allocator. (Default: 0)', type='INTEGER', value='-1', read_only='Y')
 (name='blobstripe', description='', type='BOOLEAN', value='ON', read_only='Y')
 (name='blocking_latches', description='Block on latch rather than deadlock', type='BOOLEAN', value='OFF', read_only='N')
-(name='blocking_physrep', description='Physical replicant blocks on select. (Default: off)', type='BOOLEAN', value='ON', read_only='N')
+(name='blocking_physrep', description='Physical replicant blocks on select. (Default: on)', type='BOOLEAN', value='ON', read_only='N')
 (name='broadcast_check_rmtpol', description='Check rmtpol before sending triggers', type='BOOLEAN', value='ON', read_only='N')
 (name='broken_max_rec_sz', description='', type='INTEGER', value='0', read_only='Y')
 (name='broken_num_parser', description='', type='BOOLEAN', value='OFF', read_only='Y')
@@ -742,7 +742,7 @@
 (name='physrep_max_rollback', description='Maximum logs physrep can rollback. (Default: 0)', type='INTEGER', value='0', read_only='N')
 (name='physrep_metadb_host', description='List of physical replication metadb cluster hosts.', type='STRING', value=NULL, read_only='Y')
 (name='physrep_metadb_name', description='Physical replication metadb cluster name.', type='STRING', value=NULL, read_only='Y')
-(name='physrep_pollms', description='Physical replicant poll interval in milliseconds. (Default: 200)', type='INTEGER', value='0', read_only='N')
+(name='physrep_pollms', description='Physical replicant poll interval in milliseconds. (Default: 0)', type='INTEGER', value='0', read_only='N')
 (name='physrep_reconnect_interval', description='Reconnect interval for physical replicants (Default: 600)', type='INTEGER', value='3600', read_only='N')
 (name='physrep_reconnect_penalty', description='Physrep wait seconds before retry to the same node. (Default: 5)', type='INTEGER', value='0', read_only='N')
 (name='physrep_repl_host', description='Current physrep host.', type='STRING', value=NULL, read_only='Y')
