[chord] Re: problem with running sfsrodb

[Y Chen]

Hi

Thank very much for the reply.

(1) I found out the reason. Seems a small bug at function store_direcory() of
<sfsrodb.C>, about line 504:
======================================
void store_directory (sfsro_inode *inode, sfs_hash *fh, sfsro_data *directory)
{
  // XXX???  sfsro_data dat (SFSRO_DIRBLK);
  size_t calllen = 0;
  char *callbuf = NULL;
  xdrsuio x (XDR_ENCODE);

(504) if (xdr_sfsro_data ( x.xdrp(), directory)) {

=> if (xdr_sfsro_data ( x.xdrp(), &directory)) {

...

}

("&" was missed here)
=================================================

(2) Can I ask the detail of dbm?

dbm: vnode_num control_socket num_trials data_size file <f or s> nops seed [bw-f
ile]

- vnode_num: why there are only 49 nodes exist, I can still set vnode_num=1000?
- num_trials: What's the biggest block number can I put here?
- data_size: Is there any limitation of the size?
- file: what's this for?
- <f or s> : is that 'f' means search block operation, and 's' means insert
block operation?
- nops: is it the lookup times, which need to be set because normally cannot
find the result in one lookup?
- seed: if I set seed=1 when insert the block, can I find the same block with
seed=1 with dbm?
- [bw-file]: what's this for?

(3) How to delete block I stored into the Chord system? Is there any information
showing how blocks alocated to each peer?

Thanks very much!

Yin



Quoting Frank Dabek <fdabek at MIT.EDU>:

> This trace looks suspicious: exp_dir is an unreasonable pointer.
>
> let's back up a bit: can you run lsd and store blocks using the 'dbm'
> program?
>
> --Frank
>
> Y Chen wrote:
> > Hi
> >
> > The problem passes through main() function of sfsrodb.C and comes with
> error
> > when reaches the last line of main()
> >
> > main()
> > {...
> > return (sfsrodb_main (exp_dir, sk_file));
> > }
> >
> > Can step futher till the line 812 of sfsrodb.C
> >
> > Near the beginning of the sfsrodb_main() function:
> >
> > int sfsrodb_main (const str root, const str keyfile)
> > {
> > ...
> >
> > 812  dhash_cli = New refcounted <dhashclient> (lsd_socket);
> > ...
> >
> > Sorry to trouble you lot!
> >
> > Yin
> >
> >
> >
> >
> > Quoting s0231189 at sms.ed.ac.uk:
> >
> >
> >>Hi
> >>
> >>sorry, please ignor my previous message,
> >>the result is as follow:
> >>
> >>
> >>>gdb chord-build/sfsrodb/sfsrodb
> >>
> >>(gdb)run -s key_file -d tmp
> >>Starting program: /home/yin/chord-build/sfsrodb/sfsrodb -s key_file -d tmp
> >>
> >>Program received signal SIGSEGV, Segmentation fault.
> >>0x400fea3c in rpc_traverse<2147483647u> () from /lib/libsfsmisc.so.0
> >>(gdb) bt
> >>#0  0x400fea3c in rpc_traverse<2147483647u> () from /lib/libsfsmisc.so.0
> >>#1  0x4030dea1 in rpc_traverse<XDR*> () from /lib/libsvc.so.0
> >>#2  0x40312e9c in rpc_traverse<XDR*, sfsro_dirent> () from /lib/libsvc.so.0
> >>#3  0x4030df43 in rpc_traverse<XDR*> () from /lib/libsvc.so.0
> >>#4  0x4030e127 in rpc_traverse<XDR*> () from /lib/libsvc.so.0
> >>#5  0x4030a382 in xdr_sfsro_data () from /lib/libsvc.so.0
> >>#6  0x0804d68b in store_directory (inode=0xbffff5f0, fh=0xbffffaa0,
> >>    directory=0xffffffff) at xdrmisc.h:386
> >>#7  0x0804e901 in recurse_path (path={b = {p = 0x8087e18}}, fh=0xbffffaa0)
> >>    at /home/yin/sfsnet/sfsrodb/sfsrodb.C:728
> >>#8  0x0804fd01 in sfsrodb_main (root=Cannot access memory at address
> >>0xffffffff
> >>) at str.h:45
> >>#9  0x08051c23 in main (argc=0, argv=0xbffffd14) at str.h:101
> >>
> >>
> >>
> >>Thanks a lot
> >>
> >>Yin
> >>
> >>Quoting Frank Dabek <fdabek at MIT.EDU>:
> >>
> >>
> >>>
> >>>Y Chen wrote:
> >>>
> >>>>Hi
> >>>>
> >>>>I followed Chord HOWTO and tried sfsrodb for several times,
> >>>>
> >>>>chord-build/sfsrodb/sfsrodb -s key_file -d tmp
> >>>>
> >>>>but the result is :
> >>>>
> >>>>"Segmentation fault"
> >>>>
> >>>>What's the problem of this?
> >>>>
> >>>
> >>>The problem is that the program accessed memory that it is not allowed
> >>>to access by the operating system. This is usually the result of a bug
> >>>in the program.
> >>>
> >>>If you provide me with a backtrace of the crash I might be able to debug
> >>>it. Try:
> >>>
> >>>gdb sfsrodb <name of core file, e.g. sfsrodb.core>
> >>>(gdb) bt
> >>>
> >>>and send me the results.
> >>>
> >>>However, sfsrodb is not under active development. I can't guarantee that
> >>>we will fix any bug in a timely  manner.
> >>>
> >>>--Frank
> >>>
> >>>
> >>>>Cheers,
> >>>>
> >>>>Yin
> >>>
> >>
> >>
> >
> >
>