Re: [Xen-devel] [PATCH v6 COLO 07/15] implement the cmdline for COLO

[Yang Hongyang <yanghy@xxxxxxxxxxxxxx>]

On 06/16/2015 07:19 PM, Ian Campbell wrote:
> On Mon, 2015-06-08 at 11:45 +0800, Yang Hongyang wrote:
> > From: Wen Congyang <wency@xxxxxxxxxxxxxx>
> >
> > Add a new option -c to the command 'xl remus'. If you want
> > to use COLO HA instead of Remus HA, please use -c option.
> >
> > Update man pages to reflect the addition of a new option to
> > 'xl remus' command.
> >
> > Also add a new option -c to the internal command 'xl migrate-receive'.
> I asked about whether COLO was an extension or a peer to Remus in an
> earlier patch. the answer may have an impact here too.
We implemented COLO based on Remus, so we assume it is an extension to Remus.

> > @@ -498,6 +501,11 @@ Disable network output buffering. Requires enabling unsafe 
> > mode.
> >
> >   Disable disk replication. Requires enabling unsafe mode.
> >
> > +=item B<-c>
> > +
> > +Enable COLO HA. It is conflict with B<-i> and B<-b>, and memory
> "It conflicts with" or "This conflicts with".
>
> > +checkpoint compression must be disabled.
> > +
> >   =back
> >
> >   =item B<pause> I<domain-id>
> > diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
> > index 1145ae4..7df2466 100644
> > --- a/tools/libxl/libxl.c
> > +++ b/tools/libxl/libxl.c
> > @@ -811,6 +811,22 @@ int libxl_domain_remus_start(libxl_ctx *ctx, 
> > libxl_domain_remus_info *info,
> >           goto out;
> >       }
> >
> > +    /* The caller must set this defbool */
> > +    if (libxl_defbool_is_default(info->colo)) {
> > +        LOG(ERROR, "colo mode must be enabled/disabled");
> As I wondered earlier -- this suggests it should not be a defbool, or
> that the interfaces should split.
>
> > +        rc = ERROR_FAIL;
> > +        goto out;
> > +    }
> > +
> > +    if (libxl_defbool_val(info->colo)) {
> > +        libxl_defbool_setdefault(&info->compression, false);
> Assuming this isn't invalidated by the above comments, you should make
> the existing:
>   libxl_defbool_setdefault(&info->compression, true);
> into
>   libxl_defbool_setdefault(&info->compression, libxl_defbool_val(colo));
>
> and then do an error check later.
>
> > +        if (libxl_defbool_val(info->compression)) {
> > +            LOG(ERROR, "cannot use memory checkpoint compression in COLO 
> > mode");
> > +            rc = ERROR_FAIL;
> > +            goto out;
> > +        }
> > +    }
> > +
> >       libxl_defbool_setdefault(&info->allow_unsafe, false);
> >       libxl_defbool_setdefault(&info->blackhole, false);
> >       libxl_defbool_setdefault(&info->compression, true);
> > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> > index adfadd1..4bbadd3 100644
> > --- a/tools/libxl/xl_cmdimpl.c
> > +++ b/tools/libxl/xl_cmdimpl.c
> > @@ -4273,6 +4273,9 @@ static void migrate_receive(int debug, int daemonize, int 
> > monitor,
> >       dom_info.send_fd = send_fd;
> >       dom_info.migration_domname_r = &migration_domname;
> >       dom_info.checkpointed_stream = remus;
> > +    if (remus == LIBXL_CHECKPOINTED_STREAM_COLO)
> > +        /* COLO uses stdout to send control message to master */
> > +        dom_info.quiet = 1;
> Please set a const char * to either "COLO" or "Remus" here and use it
> everywhere you've currently got an open coded decision on that.
>
> >       rc = create_domain(&dom_info);
> >       if (rc < 0) {
> > @@ -4287,7 +4290,8 @@ static void migrate_receive(int debug, int daemonize, int 
> > monitor,
> >           /* If we are here, it means that the sender (primary) has crashed.
> >            * TODO: Split-Brain Check.
> >            */
> > -        fprintf(stderr, "migration target: Remus Failover for domain %u\n",
> > +        fprintf(stderr, "migration target: %s Failover for domain %u\n",
> > +                remus == LIBXL_CHECKPOINTED_STREAM_COLO ? "COLO" : "Remus",
> >                   domid);
> >
> >           /*
> > @@ -4304,15 +4308,21 @@ static void migrate_receive(int debug, int daemonize, 
> > int monitor,
> >               rc = libxl_domain_rename(ctx, domid, migration_domname,
> >                                        common_domname);
> >               if (rc)
> > -                fprintf(stderr, "migration target (Remus): "
> > +                fprintf(stderr, "migration target (%s): "
> >                           "Failed to rename domain from %s to %s:%d\n",
> > +                        remus == LIBXL_CHECKPOINTED_STREAM_COLO ? "COLO" : 
> > "Remus",
> >                           migration_domname, common_domname, rc);
> >           }
> >
> > +        if (remus == LIBXL_CHECKPOINTED_STREAM_COLO)
> > +            /* The guest is running after failover in COLO mode */
> > +            exit(rc ? -ERROR_FAIL: 0);
> > +
> >           rc = libxl_domain_unpause(ctx, domid);
> >           if (rc)
> > -            fprintf(stderr, "migration target (Remus): "
> > +            fprintf(stderr, "migration target (%s): "
> >                       "Failed to unpause domain %s (id: %u):%d\n",
> > +                    remus == LIBXL_CHECKPOINTED_STREAM_COLO ? "COLO" : "Remus",
> >                       common_domname, domid, rc);
> >
> >           exit(rc ? -ERROR_FAIL: 0);
> > @@ -4458,7 +4468,7 @@ int main_migrate_receive(int argc, char **argv)
> >       int debug = 0, daemonize = 1, monitor = 1, remus = 0;
> >       int opt;
> >
> > -    SWITCH_FOREACH_OPT(opt, "Fedr", NULL, "migrate-receive", 0) {
> > +    SWITCH_FOREACH_OPT(opt, "Fedrc", NULL, "migrate-receive", 0) {
> >       case 'F':
> >           daemonize = 0;
> >           break;
> > @@ -4470,8 +4480,10 @@ int main_migrate_receive(int argc, char **argv)
> >           debug = 1;
> >           break;
> >       case 'r':
> > -        remus = 1;
> > +        remus = LIBXL_CHECKPOINTED_STREAM_REMUS;
> >           break;
> > +    case 'c':
> > +        remus = LIBXL_CHECKPOINTED_STREAM_COLO;
> >       }
> >
> >       if (argc-optind != 0) {
> > @@ -7958,15 +7970,18 @@ int main_remus(int argc, char **argv)
> >       pid_t child = -1;
> >       uint8_t *config_data;
> >       int config_len;
> > +    int interval = 0;
> >
> >       memset(&r_info, 0, sizeof(libxl_domain_remus_info));
> >       /* Defaults */
> >       r_info.interval = 200;
> >       libxl_defbool_setdefault(&r_info.blackhole, false);
> > +    libxl_defbool_setdefault(&r_info.colo, false);
> >
> > -    SWITCH_FOREACH_OPT(opt, "Fbundi:s:N:e", NULL, "remus", 2) {
> > +    SWITCH_FOREACH_OPT(opt, "Fbundi:s:N:ec", NULL, "remus", 2) {
> >       case 'i':
> >           r_info.interval = atoi(optarg);
> > +        interval = 1;
> This duplication of r_info.interval and interval seems odd. Perhaps
> interval is really "interval_was_set" but even so I'm not sure this
> would be better achieved with some more refactoring.
>
> >           break;
> >       case 'F':
> >           libxl_defbool_set(&r_info.allow_unsafe, true);
> > @@ -7992,11 +8007,28 @@ int main_remus(int argc, char **argv)
> >       case 'e':
> >           daemonize = 0;
> >           break;
> > +    case 'c':
> > +        libxl_defbool_set(&r_info.colo, true);
> >       }
> >
> >       domid = find_domain(argv[optind]);
> >       host = argv[optind + 1];
> >
> > +    if (libxl_defbool_val(r_info.colo)) {
> > +        if (!interval)
> > +            r_info.interval = 0;
> > +
> > +        if (r_info.interval || libxl_defbool_val(r_info.blackhole)) {
> > +            perror("option -c is conflict with -i or -b");
> "...-c conflicts with..."
>
> > +            exit(-1);
> > +        }
> > +
> > +        if (libxl_defbool_is_default(r_info.compression)) {
> > +            perror("option -u must be specified when using COLO");
> Then enforce it using setdefault I think instead of making the user jump
> through a pointless hoop.
>
> Ian.
>
> .
--
Thanks,
Yang.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel