Databases
StackOverflow2013
Postsdbo
POHow to access MySQL from MPI program (use MPICH2)?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to access MySQL from MPI program (use MPICH2)?
    primarykey
    data
    text
    <p>I have huge database (DBMS = MySQL) that I access from an MPI program (using MPICH2). In this program, I just want to know about time to execute sql query. It's reference to my other parallel program.</p> <p>When the code's run from Visual Studio C++, it runs well (I get the output). But when it's runed use <code>mpiexec</code>, there's no output and no error message. Otherwise, when I try a simple program (no mysql code, use mpiexec), it runs well (there is output). Should I not be using the mysql and mpi libraries together?</p> <p>The code like this : </p> <pre><code>#include &lt;stdio.h&gt; #include &lt;windows.h&gt; #include &lt;mysql.h&gt; #include &lt;iostream&gt; #include &lt;winsock.h&gt; #include &lt;mpi.h&gt; #include &lt;stdlib.h&gt; using namespace std; //namespace for error handling namespace ekception{ struct error{ const char *p; error(const char *q){ p=q; } }; } int main(int argc, char *argv[]){ MYSQL mysql,*sock; MYSQL_RES *res; int state; char *host="localhost"; char *user="root"; char *password=""; char *dbName="sp"; double start,finish,time; long j; char s[]="SELECT COUNT(kolom2) FROM coba WHERE kolom1&lt;="; char query[BUFSIZ]; MPI_Init(&amp;argc,&amp;argv); for(j=250000;j&lt;=25000000;j+=250000){ sprintf_s(query,"%s%d",s,j); start=MPI_Wtime(); try{ mysql_init(&amp;mysql); if(!(sock=mysql_real_connect(&amp;mysql,host,user,password,dbName,0,NULL,0))){ throw ekception::error("Connection failed\n"); } mysql.reconnect=1; state=mysql_query(sock,query); if(state!=0){ throw ekception::error("Query execution Failed\n"); } res=mysql_store_result(sock); mysql_free_result(res); mysql_close(sock); } catch(ekception::error e){ printf("%s\n",e.p); } finish=MPI_Wtime(); time=finish-start; printf("Data size = %d *** time = %f\n",j,time); } MPI_Finalize(); getchar(); return 0; } </code></pre> <p>Thanks in Advance</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USrene
    1. UStitia
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to access MySQL from MPI program (use MPICH2)?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow to access MySQL from MPI program (use MPICH2)?
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    3. VO
      singulars
      1. POHow to access MySQL from MPI program (use MPICH2)?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThis might be stupid, but I still have to ask... You have `localhost` as your server name. Are processes started with `mpiexec` also running on `localhost` or are they sent to some backend compute nodes?
      singulars
      1. POHow to access MySQL from MPI program (use MPICH2)?
      1. USHristo Iliev
    2. COyes, i use localhost as my mysql server. yes, i try it on localhost only (just 1 PC).
      singulars
      1. POHow to access MySQL from MPI program (use MPICH2)?
      1. UStitia
    3. COCould you try to remove the `getchar()` call at the end of `main()`? Console input doesn't play well with MPI.
      singulars
      1. POHow to access MySQL from MPI program (use MPICH2)?
      1. USHristo Iliev
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload