MySQL Cluster NDB MGM API on Windows

As MySQL Cluster is now available, and GA, on Windows, maybe it's time for some NDB API coding on that platform, right? The reason for this might, as it is in my case, be that Windows is a pretty good GUI Desktop platform, and MySQL Cluster / NDB really needs something like this. Those of you who have followed and used Cluster for a while, might remember my ndbtop tool that I created way back, and which is a MySQL Cluster monitor for Linux using ncurses. This is still useful I guess, but as far as a nice GUI presentation goes, ncurses leaves a lot to be desiered, to say the least.

So where do we start on Windows then? Well, to be honest, MySQL Cluster on Windows doesn't currently come with an installer, it's just a .zip file to unpack. But we are only using NDBAPI and the NDBMGMAPI, so that it no big deal, right? Just unpack the zip-file, write your C or C++ and compile with the supplied includefiles and libraries? Right?

Nope, sorry to disappoint you, but it is more complicated than that. MySQL Cluster on Windows doesn't include ndbapi in the binary release. You might think it does, considering there is a ndbapi.lib file and stuff. But this is not enough, you want the includefiles and also a few more libraries. Also, these are static libraries, which will confuse things a bit. Let me explain this first:

Microsoft has a habit of introducing new things in the C and C++ compilers that rely on things in the C runtime library. This is not a good habit, as it break compatability when building static libraries in particular. What happens is that the static library contains references to the embedded C RTL, and if I link with that library, I will have conflicts between the C RTL that my program wants, and the one that is in the library. And if I link my application without including the standard C RTL, and rely on the one in the library I am linking with, then things may break as my compiled code may contain references that are part of the C RTL I am using, but isn't part of the C RTL of the library I am linking with.

Anyone who has, on Windows, linked with the static MySQL Client library (mysqlclient.lib) knows what I am talking about here, and you also know the solution out of this mess: Compile the library yourself with the Microsoft compiler you use for your application.

So we need to revert to the source anyway. I use Visual Studio 2010 these days, but this is not really supported by the MySQL Build process, or to be honest, I haven't even tried it. I have VS 2008 installed on the same machine, build the project for that, and then let VS 2010 convert it.

So go along and do what is usually done when building MySQL from Source on Windows:

• Get cmake from http://www.cmake.org.
• Use a DOS prompt and go to the main directory where you unpacked the MySQL Cluster sources.
• In the DOS Window run the command:
  win\configure.js WITH_NDBCLUSTER_STORAGE_ENGINE
• In the DOS Window run the command:
  win\build-vs9
• All this will create a MySql.sln file in the main directory of the MySQL Cluster sources.
• Open the MySql.sln file with the Visual Stuio versioon of your choise.

Having done all this, select the Release build and build the following projects:

• mysys (mysys\Release\mysys.lib)
  
• strings (strings\Release\strings.lib)
  
• ndbgeneral (storage\ndb\src\common\util\Release\ndbgeneral.lib)
  
• ndbportlib (storage\ndb\src\common\portlib\Release\ndbportlib.lib)
  
• ndblogger (storage\ndb\src\common\logger\Release\ndblogger.lib)
  
• ndbtrace (storage\ndb\src\common\debugger\Release\ndbtrace.lib)
  
• ndbmgmapi (storage\ndb\src\mgmapi\Release\ndbmgmapi.lib)

You can of course build the whole shebang also, if you so wish. Now, after all this fun, what's the next step? First copy the above libraries (the paths are in prenteses after the library names) to some easy to remember place. I have downloaded the MySQL Cluster Binary also, and have placed these files in a new ndbapi directory under the lib directory. In addition, you need to copy a few includefiles, in my case to the MySQL Cluster binary include directory:

• ndb_init.h (storage\ndb\include\ndb_init.h)
  
• ndb_types.h (storage\ndb\include\ndb_types.h)
• ndb_constants.h (storage\ndb\include\ndb_constants.h)
• the whole mgmapi directory (storage\ndb\include\mgmapi)

The files are copied in my case to the location where I have the MySQL Cluster Binary includefiles, and the mgmapi directory is copied as sibdirectory to this).

Whoa, that was a lot of fun and copying! Right? Or?
Anyway, you should now be able to build a MySQL Cluster NDB MGM API application. Note that we did a Release build of the libaries, so to avoid warnings, build your application in Release build also. Include the path to the MySQL Cluster Binary include directory for the compiler and point the linked to the lib directory created above. And then one more this:
The static libraries already have a reference to the C Run Time library, so tell Visual Studio to disreard the LIBCMT default library. You do this Linker->Input settings in the "Ignore Specific Default Libraries", which you set to LIBCMT. If you build from the commandline, this is the same as /NODEFAULTLIB:"LIBCMT"

Having done all this, your application should compile, link and run just fine. For your reference, here is a Windows command-line program that will show the nodes in the Cluster and the status of them. And yes, the whole idea was to build a GUI application, but it's just too much code for a sample like this. Here you go anyway:

#include
#include
#include
#include
#include
#include
#include

typedef struct tagTEXTMAP
{
int nValue;
char *pText;
} TEXTMAP, *PTEXTMAP;

TEXTMAP g_NodeType[] = {
{ NDB_MGM_NODE_TYPE_API, "API" },
{ NDB_MGM_NODE_TYPE_NDB, "Data" },
{ NDB_MGM_NODE_TYPE_MGM, "MGM" },
{ NDB_MGM_NODE_TYPE_UNKNOWN, "Unknown" },
{ 0, NULL }};

TEXTMAP g_NodeStatus[] = {
{ NDB_MGM_NODE_STATUS_UNKNOWN, "Unknown status" },
{ NDB_MGM_NODE_STATUS_NO_CONTACT, "No contact" },
{ NDB_MGM_NODE_STATUS_NOT_STARTED, "Not started" },
{ NDB_MGM_NODE_STATUS_STARTING, "Starting" },
{ NDB_MGM_NODE_STATUS_STARTED, "Started" },
{ NDB_MGM_NODE_STATUS_SHUTTING_DOWN, "Shutting down" },
{ NDB_MGM_NODE_STATUS_RESTARTING, "Restarting" },
{ NDB_MGM_NODE_STATUS_SINGLEUSER, "Single user" },
{ NDB_MGM_NODE_STATUS_RESUME, "Resuming" },
{ 0, NULL }};

int main(int argc, char *argv[])
{
NdbMgmHandle hMgm;
ndb_mgm_cluster_state *pState;
ndb_mgm_node_state *pNodeState;
PTEXTMAP pMap;
char *pNodeType;
char *pNodeStatus;
int i;

// Check arguments.
if(argc < 2)
{
fprintf(stderr, "Usage: %s \n", argv[0]);
return 1;
}
ndb_init();
hMgm = ndb_mgm_create_handle();

// Connect to mgm server.
ndb_mgm_set_connectstring(hMgm, argv[1]);
if(ndb_mgm_connect(hMgm, 0, 0, 0) == -1)
{
fprintf(stderr, "Error connecting to cluster\n");
return 1;
}

pState = ndb_mgm_get_status(hMgm);
for(i = 0; i < no_of_nodes; i++)
{
pNodeState = &pState->node_states[i];
for(pMap = g_NodeType; pMap->pText != NULL && pMap->nValue != pNodeState->node_type; pMap++)
;
if(pMap->pText == NULL)
pNodeStatus = "Unknown type";
else
pNodeType = pMap->pText;
for(pMap = g_NodeStatus; pMap->pText != NULL && pMap->nValue != pNodeState->node_status; pMap++)
;
if(pMap->pText == NULL)
pNodeStatus = "Unknown status";
else
pNodeStatus = pMap->pText;

printf("Node id: %d at %s. Type: %s. Status: %s\n", pNodeState->node_id, pNodeState->connect_address,
pNodeType, pNodeStatus);
}
}

/Karlsson