FreeTDS Development Group

[craigs <s.craig AT andronics.com>]

here is a detailed list of what we are running! we have a suse 9.2 linux 
server, using tds version 4.2 for connection pooling, snapshot 
freetds-0.64.dev.20041207, client programs written in C using db-lib.  
the pool goes down at least a few times every hour, we are using 3 max 
connections and receiving approx 1200 clients an hour and each client 
does at least 2 querys and an insert with few doing 1 or 2 more.

we have written a process watcher that watchs the connection pool and 
restarts it if it crashes, before we added a patch it would take the 
connection pool nearly a minute to come back up, it wouldnt release the 
socket, or the socket had to wait to time out, now the pool comes back 
up again within a few seconds.

here is the function we have changed, basically all we did was add 2 
lines. 
Location of file changed:   /freetds//src/pool/main.c
Function changed:              void pool_main_loop(TDS_POOL * pool)

here is a copy of the function with changes highlighted in ******

Hope this is off use to someone!

void pool_main_loop(TDS_POOL * pool)
{
   TDS_POOL_USER *puser;
   TDS_POOL_MEMBER *pmbr;
   struct sockaddr_in sin;
   int s, maxfd, i;
   int retval;
   fd_set rfds;

/* fix me -- read the interfaces file and bind accordingly */
   sin.sin_addr.s_addr = INADDR_ANY;
   sin.sin_port = htons(pool->port);
   sin.sin_family = AF_INET;

   if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
       perror("socket");
       exit(1);
   }

********************************************************************************
   /* Set socket options so we can restart the pool */
   int socktrue = 1;
   setsockopt(s,SOL_SOCKET,SO_REUSEADDR,&socktrue,sizeof socktrue);
*********************************************************************************

   fprintf(stderr, "Listening on port %d\n", pool->port);
   if (bind(s, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
       perror("bind");
       exit(1);
   }
   listen(s, 5);

   FD_ZERO(&rfds);
   FD_SET(s, &rfds);
   maxfd = s;

   while (!term) {
       fprintf(stderr, "waiting for a connect\n");
       retval = select(maxfd + 1, &rfds, NULL, NULL, NULL);
       if (term)
           continue;

       /* process the sockets */
       if (FD_ISSET(s, &rfds)) {
           puser = pool_user_create(pool, s, &sin);
       }
       pool_process_users(pool, &rfds);
       pool_process_members(pool, &rfds);
       /* back from members */
       if (waiters) {
           pool_schedule_waiters(pool);
       }

       FD_ZERO(&rfds);
       /* add the listening socket to the read list */
       FD_SET(s, &rfds);
       maxfd = s;

       /* add the user sockets to the read list */
       for (i = 0; i < pool->max_users; i++) {
           puser = (TDS_POOL_USER *) & pool->users[i];
           /* skip dead connections */
           if (!IS_TDSDEAD(puser->tds)) {
               if (puser->tds->s > maxfd)
                   maxfd = puser->tds->s;
               FD_SET(puser->tds->s, &rfds);
           }
       }

       /* add the pool member sockets to the read list */
       for (i = 0; i < pool->num_members; i++) {
           pmbr = (TDS_POOL_MEMBER *) & pool->members[i];
           if (!IS_TDSDEAD(pmbr->tds)) {
               if (pmbr->tds->s > maxfd)
                   maxfd = pmbr->tds->s;
               FD_SET(pmbr->tds->s, &rfds);
           }
       }
   }            /* while !term */
   close(s);
   for (i = 0; i < pool->max_users; i++) {
       puser = (TDS_POOL_USER *) & pool->users[i];
       if (!IS_TDSDEAD(puser->tds)) {
           fprintf(stderr, "Closing user %d\n", i);
           tds_close_socket(puser->tds);
       }
   }
   for (i = 0; i < pool->num_members; i++) {
       pmbr = (TDS_POOL_MEMBER *) & pool->members[i];
       if (!IS_TDSDEAD(pmbr->tds)) {
           fprintf(stderr, "Closing member %d\n", i);
           tds_close_socket(pmbr->tds);
       }
   }
}

Brian Bruns wrote:

> Craig,
>
> Wanna send along the patch for that?  I'll merge it.  I've been
> planning on spending some time on this, and may get around to it this
> weekend.  What is your server/version?
>
> I'll try to do some load testing and see if I can reproduce your error
> locally, and failing that scan the code for something.
>
> Brian
>
> On Thu, 09 Dec 2004 09:17:32 +0000, craigs <s.craig AT andronics.com> wrote:
>  
>
> > Frediano Ziglio wrote:
> >
> >
> >
> >    
> >
> > > Il mer, 2004-12-08 alle 13:52, craigs ha scritto:
> > >
> > >
> > >      
> > >
> > > > Brian Bruns wrote:
> > > >
> > > > Program received signal SIGSEGV, Segmentation fault.
> > > > 0x0804b5b0 in pool_process_users (pool=0x804d008, fds=0xbfffdbd0) at
> > > > user.c:131
> > > > 131                     if (FD_ISSET(puser->tds->s, fds)) {
> > > >
> > > > is this any help?
> > > >
> > > > Shaun.
> > > >
> > > >
> > > >
> > > >        
> > > Yes, probably puser->tds == NULL or puser->tds->s < 0. In other words
> > > connection closed
> > >
> > > freddy77
> > >
> > >
> > >
> > >      
> > Any ideas why the connection is closing, would it be on my C clients
> > side or maybe something to do with ms sql.  when it does crash it takes
> > nearly a minute to come up again which can cause problems for ourselfs,
> > we have added a line in pool_main_loop which releases the socket as soon
> > it crashes, our up time again has been greatly reduced because of this
> > line,  would this be of any use to anyone?
> >
> >
> >
> >    
> >
> > > _______________________________________________
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> > > http://lists.ibiblio.org/mailman/listinfo/freetds
> > >
> > >
> > >      
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> >
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