Re: [Moosefs-users] changelogs on the metalogger

[Bán M. <ba...@vo...>]

Hi,

I've found something:

in the masterconn.c
void masterconn_metachanges_log ...

the fprintf just write the changelogs when I stop or restart the process


178         if (eptr->logfd==NULL) {
179                 eptr->logfd = fopen("changelog_ml.0.mfs","a");
180         }
181 
182         data++;
183         version = get64bit(&data);
184         if (eptr->logfd) {
185                 fprintf(eptr->logfd,"%"PRIu64": %s\n",version,data);
186         } else {
187                 syslog(LOG_NOTICE,"lost MFS change %"PRIu64":
%s",version,data); 188         }

I've append this lines:

	if (eptr->logfd) {
		fclose(eptr->logfd);
	    eptr->logfd = NULL;
	}

It seems to work, but I'm not sure is it a good way or not, I did not
read the source code thoroughly.


Second problem:
If I stop, wait and start the metalogger server, the changelog will be
inconsistent. The changes from the master server, while the metalogger
was being stopped, not arriving after I turn it back on. 
Is there any recommendation how can I manage the metalogger servers
to keep coherent change logs after failure situation?

Miklos


On Mon, 6 Sep 2010 13:42:30 +0200
Michał Borychowski <mic...@ge...> wrote:

> Hi!
> 
> Metaloggers should continuously receive the current changes from the
> master server and write them into its own text change logs named
> changelog_ml.0.mfs. 
> 
> How do you know that in your system they are save hourly? Don't they
> increment with every change in the filesystem?
> 
> Regarding your second question - yes, this is right. For now,
> metalogger doesn't download the metadata file upon starting. We know
> about this shortcoming and we'll fix the behaviour soon.
> 
>