I've tried to copy/paste and simplify the code.
Please assume that the sql query on line #19 is correct, its actually
longer so i truncated it. getDB() returns _db.
I checked the value of _db after the sqlite3_open() fn call its a valid
handle.
I'm trying to understand fuser and lsof commands and will get back to
you.
Thanks for you help. If you have any other suggestions then please do
let me know
Thanks
Ritesh
On Tue, 2006-01-31 at 18:02, Christian Smith wrote:
> On Tue, 31 Jan 2006, Ritesh Kapoor wrote:
>
> >Regarding the configuration of NFS -
> >I have two machines with NFS on them.
> >- if i run the app on machine 1 it works properly
> >- now when i run the app on machine 2 it works properly
> >
> >But if I login to machine 2 from machine 1 and then run the app I get
> >the 'database is locked' error message.
>
>
> I assume this is using an NFS file from machine 2 from machine 1?
>
>
> >
> >The sequence of statements are -
> >
> >1 if((fp = fopen(fullFileName.c_str(),"w+")))
> >2 {
> >3 fclose(fp);
> >4 }
> >5 else
> >6 {
> >7 printf("Error creating file");
> >8 return;
> >9 }
>
>
> This bit is unnecessary. SQLite will create a file if it does not exist.
>
>
> >10 int res = sqlite3_open(fullFileName.c_str(), &_db);
> >11 if( res != SQLITE_OK )
> >12 {
> >13 printf("Error opending DB");
> >14 sqlite3_close(_db);
>
>
> _db will not be a valid handle if sqlite3_open failed.
>
>
> >15 return;
> >16 }
> >17
> >18 sqlite3_trace(getDB(),logSqlQuery,&sqlLogList);
>
>
> getDB()? Does this return _db?
>
>
> >19 string query = "create table XYZ";
> >20 res = sqlite3_exec(_db, query.c_str(), NULL , 0, &errmsg);
>
>
> This example won't work as "create table XYZ" isn't a valid complete SQL
> statement.
>
>
> >21
> >22 if(res == 5)
> >23 ....
> >
> >
> >After line #20 the value of 'res' is 5.
> >
> >I've even tried to run the app after removing line #18 which contains
> >the sqlite3_trace() fn call. But that dosen't seem to be the cause.
> >
> >I've gone through the mail archive of this list and saw that this
> >problem did appear for others as well but there the solution was to
> >check if a previously executing sql statement was still not finished
> >with its job and a another sql statement was being executed.
> >
> >Over here the first sql statement's execution returns this error.
>
>
> Could be that the incomplete statement is causing problems.
>
>
> >
> >Another assumption that I made was that the host machine locks the file
> >after I open a sqlite connection (line #10). So I should wait for it to
> >release this lock. I ran the app using GDB and after line #10 I paused
> >the app for some time hoping that the lock would go away but the problem
> >persists even after pausing for 10, 20 and 30 minutes in seperate runs.
> >
> >
> >If NFS is the problem then what configurations do I need to look at and
> >change to make my app work properly?
>
>
> Locking is handled by rpc.lockd(8). It should be started by default.
>
>
> >
> >What if the problem is with the host machine locking the file or some
> >other process running on my machine or the host machine which locks the
> >file? Is this possible?
>
>
> Possible. Check your on both machines if the file is in use.
>
>
> >
> >If yes then is there a way to find out which process is doing this
> >through the entries in /proc directory?
> >
>
>
> If on Linux, try using fuser(1) to see if other processes have the file
> open, and lsof(8) to see if the file has locks associated with it.
>
>
> >
> >Thanks,
> >Ritesh
> >
> >
> >
> >On Mon, 2006-01-30 at 19:31, [EMAIL PROTECTED] wrote:
> >> Ritesh Kapoor <[EMAIL PROTECTED]> wrote:
> >> > Yes.
> >> > My machine has NFS and the machines I log onto also have NFS. But if
> >> > this is the problem then why dosen't it appear on my machine when I run
> >> > the app.
> >>
> >> Perhaps you are using a local filesystem when you run on
> >> your machine. Or perhaps NFS is configured properly on
> >> your machine but not on the other machines.
> >>
> >>
> >> > Is there a workaround for this? without having to change the file system
> >> > from NFS.
> >> >
> >>
> >> Yes. Configure your NFS so that file locking works correctly.
> >>
> >> --
> >> D. Richard Hipp <[EMAIL PROTECTED]>
> >>
> >
> >
