本节中的示例说明了如何在单个应用程序中使用 MGM API 处理多个集群上的日志事件。

此程序的源代码可以在 NDB 集群源代码树中的 storage/ndb/ndbapi-examples/mgmapi_logevent2/main.cpp 文件中找到。

#include <mysql.h>
#include <ndbapi/NdbApi.hpp>
#include <mgmapi.h>
#include <stdio.h>
#include <stdlib.h>

/*
 * export LD_LIBRARY_PATH=../../../libmysql_r/.libs:../../../ndb/src/.libs
 */

#define MGMERROR(h) \
{ \
  fprintf(stderr, "code: %d msg: %s\n", \
          ndb_mgm_get_latest_error(h), \
          ndb_mgm_get_latest_error_msg(h)); \
  exit(-1); \
}

#define LOGEVENTERROR(h) \
{ \
  fprintf(stderr, "code: %d msg: %s\n", \
          ndb_logevent_get_latest_error(h), \
          ndb_logevent_get_latest_error_msg(h)); \
  exit(-1); \
}

int main(int argc, char** argv)
{
  NdbMgmHandle h1,h2;
  NdbLogEventHandle le1,le2;
  int filter[] = { 15, NDB_MGM_EVENT_CATEGORY_BACKUP,
		   15, NDB_MGM_EVENT_CATEGORY_CONNECTION,
		   15, NDB_MGM_EVENT_CATEGORY_NODE_RESTART,
		   15, NDB_MGM_EVENT_CATEGORY_STARTUP,
		   15, NDB_MGM_EVENT_CATEGORY_ERROR,
		   0 };
  struct ndb_logevent event1, event2;

  if (argc < 3)
  {
    printf("Arguments are <connect_string cluster 1>",
           "<connect_string cluster 2> [<iterations>].\n");
    exit(-1);
  }
  const char *connectstring1 = argv[1];
  const char *connectstring2 = argv[2];
  int iterations = -1;
  if (argc > 3)
    iterations = atoi(argv[3]);
  ndb_init();

  h1= ndb_mgm_create_handle();
  h2= ndb_mgm_create_handle();
  if ( h1 == 0 || h2 == 0 )
  {
    printf("Unable to create handle\n");
    exit(-1);
  }
  if (ndb_mgm_set_connectstring(h1, connectstring1) == -1 ||
      ndb_mgm_set_connectstring(h2, connectstring1))
  {
    printf("Unable to set connection string\n");
    exit(-1);
  }
  if (ndb_mgm_connect(h1,0,0,0)) MGMERROR(h1);
  if (ndb_mgm_connect(h2,0,0,0)) MGMERROR(h2);

  if ((le1= ndb_mgm_create_logevent_handle(h1, filter)) == 0) MGMERROR(h1);
  if ((le2= ndb_mgm_create_logevent_handle(h1, filter)) == 0) MGMERROR(h2);

  while (iterations-- != 0)
  {
    int timeout= 1000;
    int r1= ndb_logevent_get_next(le1,&event1,timeout);
    if (r1 == 0)
      printf("No event within %d milliseconds\n", timeout);
    else if (r1 < 0)
      LOGEVENTERROR(le1)
    else
    {
      switch (event1.type) {
      case NDB_LE_BackupStarted:
	printf("Node %d: BackupStarted\n", event1.source_nodeid);
	printf("  Starting node ID: %d\n", event1.BackupStarted.starting_node);
	printf("  Backup ID: %d\n", event1.BackupStarted.backup_id);
	break;
      case NDB_LE_BackupCompleted:
	printf("Node %d: BackupCompleted\n", event1.source_nodeid);
	printf("  Backup ID: %d\n", event1.BackupStarted.backup_id);
	break;
      case NDB_LE_BackupAborted:
	printf("Node %d: BackupAborted\n", event1.source_nodeid);
	break;
      case NDB_LE_BackupFailedToStart:
	printf("Node %d: BackupFailedToStart\n", event1.source_nodeid);
	break;

      case NDB_LE_NodeFailCompleted:
	printf("Node %d: NodeFailCompleted\n", event1.source_nodeid);
	break;
      case NDB_LE_ArbitResult:
	printf("Node %d: ArbitResult\n", event1.source_nodeid);
	printf("  code %d, arbit_node %d\n",
	       event1.ArbitResult.code & 0xffff,
	       event1.ArbitResult.arbit_node);
	break;
      case NDB_LE_DeadDueToHeartbeat:
	printf("Node %d: DeadDueToHeartbeat\n", event1.source_nodeid);
	printf("  node %d\n", event1.DeadDueToHeartbeat.node);
	break;

      case NDB_LE_Connected:
	printf("Node %d: Connected\n", event1.source_nodeid);
	printf("  node %d\n", event1.Connected.node);
	break;
      case NDB_LE_Disconnected:
	printf("Node %d: Disconnected\n", event1.source_nodeid);
	printf("  node %d\n", event1.Disconnected.node);
	break;
      case NDB_LE_NDBStartCompleted:
	printf("Node %d: StartCompleted\n", event1.source_nodeid);
	printf("  version %d.%d.%d\n",
	       event1.NDBStartCompleted.version >> 16 & 0xff,
	       event1.NDBStartCompleted.version >> 8 & 0xff,
	       event1.NDBStartCompleted.version >> 0 & 0xff);
	break;
      case NDB_LE_ArbitState:
	printf("Node %d: ArbitState\n", event1.source_nodeid);
	printf("  code %d, arbit_node %d\n",
	       event1.ArbitState.code & 0xffff,
	       event1.ArbitResult.arbit_node);
	break;

      default:
	break;
      }
    }

    int r2= ndb_logevent_get_next(le1,&event2,timeout);
    if (r2 == 0)
      printf("No event within %d milliseconds\n", timeout);
    else if (r2 < 0)
      LOGEVENTERROR(le2)
    else
    {
      switch (event2.type) {
      case NDB_LE_BackupStarted:
	printf("Node %d: BackupStarted\n", event2.source_nodeid);
	printf("  Starting node ID: %d\n", event2.BackupStarted.starting_node);
	printf("  Backup ID: %d\n", event2.BackupStarted.backup_id);
	break;
      case NDB_LE_BackupCompleted:
	printf("Node %d: BackupCompleted\n", event2.source_nodeid);
	printf("  Backup ID: %d\n", event2.BackupStarted.backup_id);
	break;
      case NDB_LE_BackupAborted:
	printf("Node %d: BackupAborted\n", event2.source_nodeid);
	break;
      case NDB_LE_BackupFailedToStart:
	printf("Node %d: BackupFailedToStart\n", event2.source_nodeid);
	break;

      case NDB_LE_NodeFailCompleted:
	printf("Node %d: NodeFailCompleted\n", event2.source_nodeid);
	break;
      case NDB_LE_ArbitResult:
	printf("Node %d: ArbitResult\n", event2.source_nodeid);
	printf("  code %d, arbit_node %d\n",
	       event2.ArbitResult.code & 0xffff,
	       event2.ArbitResult.arbit_node);
	break;
      case NDB_LE_DeadDueToHeartbeat:
	printf("Node %d: DeadDueToHeartbeat\n", event2.source_nodeid);
	printf("  node %d\n", event2.DeadDueToHeartbeat.node);
	break;

      case NDB_LE_Connected:
	printf("Node %d: Connected\n", event2.source_nodeid);
	printf("  node %d\n", event2.Connected.node);
	break;
      case NDB_LE_Disconnected:
	printf("Node %d: Disconnected\n", event2.source_nodeid);
	printf("  node %d\n", event2.Disconnected.node);
	break;
      case NDB_LE_NDBStartCompleted:
	printf("Node %d: StartCompleted\n", event2.source_nodeid);
	printf("  version %d.%d.%d\n",
	       event2.NDBStartCompleted.version >> 16 & 0xff,
	       event2.NDBStartCompleted.version >> 8 & 0xff,
	       event2.NDBStartCompleted.version >> 0 & 0xff);
	break;
      case NDB_LE_ArbitState:
	printf("Node %d: ArbitState\n", event2.source_nodeid);
	printf("  code %d, arbit_node %d\n",
	       event2.ArbitState.code & 0xffff,
	       event2.ArbitResult.arbit_node);
	break;

      default:
	break;
      }
    }
  }

  ndb_mgm_destroy_logevent_handle(&le1);
  ndb_mgm_destroy_logevent_handle(&le2);
  ndb_mgm_destroy_handle(&h1);
  ndb_mgm_destroy_handle(&h2);
  ndb_end(0);
  return 0;
}