[Pacemaker] [PATCH]Bug 2567 - crm resource migrate should support an optional "role" parameter

Dejan Muhamedagic dejanmm at fastmail.fm
Fri Mar 18 13:24:56 UTC 2011


Hi,

On Fri, Mar 18, 2011 at 12:21:40PM +0100, Holger Teutsch wrote:
> Hi,
> I would like to submit 2 patches of an initial implementation for
> discussion.
> 
> Patch 1 implements migration of the Master role of an m/s resource to
> another node in crm_resource
> Patch 2 adds support for the shell.

Great.

> crm_resource does this with options
> 
> "crm_resource --move --resource ms_test --master --node devel2"
> 
> The shell does the same with
> 
> "crm resource migrate ms_test:master devel2"
> 
> crm_resource insist on the options "--master --node xxx" if dealing with
> m/s resources.
> 
> It is not easy to assess the expectations that a move command should
> fulfill for something more complex than a group.
> 
> To recall:
> 
> crm_resource --move resource
> creates a "standby" rule that moves the resource off the currently
> active node
> 
> while
> 
> crm_resource --move resource --node newnode
> creates a "prefer" rule that moves the resource to the new node.
> 
> When dealing with clones and masters the behavior was random as the code
> only considers the node where the first instance of the clone was
> started.
> 
> The new code behaves consistently for the master role of an m/s
> resource. The options "--master" and "rsc:master" are somewhat redundant
> as a "slave" move is not supported. Currently it's more an
> acknowledgement of the user.
> 
> On the other hand it is desirable (and was requested several times on
> the ML) to stop a single resource instance of a clone or master on a
> specific node.
> 
> Should that be implemented by something like
>  
> "crm_resource --move-off --resource myresource --node devel2" ?
> 
> or should
> 
> crm_resource refuse to work on clones
> 
> and/or should moving the master role be the default for m/s resources
> and the "--master" option discarded ?

I think that we also need to consider the case when clone-max is
less than the number of nodes. If I understood correctly what you
were saying. So, all of move slave and move master and move clone
should be possible.

Cheers,

Dejan

> Regards
> Holger

> # HG changeset patch
> # User Holger Teutsch <holger.teutsch at web.de>
> # Date 1300439791 -3600
> # Branch mig
> # Node ID dac1a4eae844f0bd857951b1154a171c80c25772
> # Parent  b4f456380f60bd308acdc462215620f5bf530854
> crm_resource.c: Add support for move of Master role of a m/s resource
> 
> diff -r b4f456380f60 -r dac1a4eae844 tools/crm_resource.c
> --- a/tools/crm_resource.c	Thu Mar 17 09:41:25 2011 +0100
> +++ b/tools/crm_resource.c	Fri Mar 18 10:16:31 2011 +0100
> @@ -52,6 +52,7 @@
>  const char *prop_id = NULL;
>  const char *prop_set = NULL;
>  char *move_lifetime = NULL;
> +int move_master = 0;
>  char rsc_cmd = 'L';
>  char *our_pid = NULL;
>  IPC_Channel *crmd_channel = NULL;
> @@ -192,6 +193,32 @@
>      return 0;
>  }
>  
> +/* is m/s resource in master role on a host? */
> +static int
> +is_master_on(resource_t *rsc, const char *check_uname)
> +{
> +    GListPtr lpc = NULL;
> +
> +    if(rsc->variant > pe_native) {
> +        /* recursively call down */
> +	GListPtr gIter = rsc->children;
> +	for(; gIter != NULL; gIter = gIter->next) {
> +	   if(is_master_on(gIter->data, check_uname))
> +               return 1;
> +        }
> +	return 0;
> +    }
> +    
> +    for(lpc = rsc->running_on; lpc != NULL; lpc = lpc->next) {
> +	node_t *node = (node_t*)lpc->data;
> +	if(rsc->variant == pe_native && rsc->role == RSC_ROLE_MASTER
> +           && safe_str_eq(node->details->uname, check_uname)) {
> +            return 1;
> +        }
> +    }
> +    return 0;
> +}
> +
>  #define cons_string(x) x?x:"NA"
>  static void
>  print_cts_constraints(pe_working_set_t *data_set) 
> @@ -797,6 +824,7 @@
>  static int
>  move_resource(
>      const char *rsc_id,
> +    int move_master,
>      const char *existing_node, const char *preferred_node,
>      cib_t *	cib_conn) 
>  {
> @@ -935,6 +963,10 @@
>  	crm_xml_add(rule, XML_ATTR_ID, id);
>  	crm_free(id);
>  
> +        if(move_master) {
> +            crm_xml_add(rule, XML_RULE_ATTR_ROLE, "Master");
> +        }
> +
>  	crm_xml_add(rule, XML_RULE_ATTR_SCORE, INFINITY_S);
>  	crm_xml_add(rule, XML_RULE_ATTR_BOOLEAN_OP, "and");
>  	
> @@ -1093,6 +1125,8 @@
>      crm_free(prefix);
>  }	
>  
> +/* out of single letter options */
> +#define OPT_MASTER (256 + 'm')
>  static struct crm_option long_options[] = {
>      /* Top-level Options */
>      {"help",    0, 0, '?', "\t\tThis text"},
> @@ -1120,10 +1154,10 @@
>      {"get-property",    1, 0, 'G', "Display the 'class', 'type' or 'provider' of a resource", 1},
>      {"set-property",    1, 0, 'S', "(Advanced) Set the class, type or provider of a resource", 1},
>      {"move",    0, 0, 'M',
> -     "\t\tMove a resource from its current location, optionally specifying a destination (-N) and/or a period for which it should take effect (-u)"
> +     "\t\tMove a resource from its current location, optionally specifying a role (--master), a destination (-N) and/or a period for which it should take effect (-u)"
>       "\n\t\t\t\tIf -N is not specified, the cluster will force the resource to move by creating a rule for the current location and a score of -INFINITY"
>       "\n\t\t\t\tNOTE: This will prevent the resource from running on this node until the constraint is removed with -U"},
> -    {"un-move", 0, 0, 'U', "\tRemove all constraints created by a move command"},
> +    {"un-move", 0, 0, 'U', "\t\tRemove all constraints created by a move command"},
>      
>      {"-spacer-",	1, 0, '-', "\nAdvanced Commands:"},
>      {"delete",     0, 0, 'D', "\t\tDelete a resource from the CIB"},
> @@ -1137,6 +1171,7 @@
>      {"resource-type",	1, 0, 't', "Resource type (primitive, clone, group, ...)"},
>      {"parameter-value", 1, 0, 'v', "Value to use with -p, -g or -d"},
>      {"lifetime",	1, 0, 'u', "\tLifespan of migration constraints\n"},
> +    {"master",    	0, 0, OPT_MASTER, "\t\tMaster role for migration constraints\n"},
>      {"meta",		0, 0, 'm', "\t\tModify a resource's configuration option rather than one which is passed to the resource agent script. For use with -p, -g, -d"},
>      {"utilization",	0, 0, 'z', "\tModify a resource's utilization attribute. For use with -p, -g, -d"},
>      {"set-name",        1, 0, 's', "\t(Advanced) ID of the instance_attributes object to change"},
> @@ -1162,6 +1197,7 @@
>      {"-spacer-",	1, 0, '-', " crm_resource --resource myResource --move", pcmk_option_example},
>      {"-spacer-",	1, 0, '-', "Move 'myResource' to a specific machine:", pcmk_option_paragraph},
>      {"-spacer-",	1, 0, '-', " crm_resource --resource myResource --move --node altNode", pcmk_option_example},
> +    {"-spacer-",	1, 0, '-', " crm_resource --resource myMsResource --master --move --node altNode", pcmk_option_example},
>      {"-spacer-",	1, 0, '-', "Allow (but not force) 'myResource' to move back to its original location:", pcmk_option_paragraph},
>      {"-spacer-",	1, 0, '-', " crm_resource --resource myResource --un-move", pcmk_option_example},
>      {"-spacer-",	1, 0, '-', "Tell the cluster that 'myResource' failed:", pcmk_option_paragraph},
> @@ -1269,7 +1305,10 @@
>  	    case 'A':
>  	    case 'a':
>  		rsc_cmd = flag;
> -		break;	
> +		break;
> +            case OPT_MASTER:
> +                move_master = 1;
> +                break;
>  	    case 'p':
>  	    case 'g':
>  	    case 'd':
> @@ -1482,7 +1521,7 @@
>  	    rc = cib_NOTEXISTS;
>  	    goto bail;
>  	} 
> -	rc = move_resource(rsc_id, NULL, NULL, cib_conn);
> +	rc = move_resource(rsc_id, 0, NULL, NULL, cib_conn);
>  
>      } else if(rsc_cmd == 'M') {
>  	node_t *dest = NULL;
> @@ -1514,21 +1553,38 @@
>  		    "%s is not a known node\n", host_uname);
>  	    rc = cib_NOTEXISTS;
>  
> +        } else if(host_uname != NULL
> +                  && rsc->variant == pe_master && ! move_master) {
> +            CMD_ERR("Error performing operation: "
> +                    "must specify --master for move of m/s resource %s to %s\n",
> +                    rsc_id, host_uname);
> +
> +        } else if(host_uname != NULL
> +                  && rsc->variant == pe_master && move_master && is_master_on(rsc, host_uname)) {
> +            CMD_ERR("Error performing operation: "
> +                    "%s is already active on %s with role Master\n",
> +                    rsc_id, host_uname);
> +
>  	} else if(host_uname != NULL
> +                  && rsc->variant != pe_master
>  		  && safe_str_eq(current_uname, host_uname)) {
>  	    CMD_ERR("Error performing operation: "
>  		    "%s is already active on %s\n",
>  		    rsc_id, host_uname);
>  
> +        } else if(host_uname == NULL && rsc->variant == pe_master) {
> +	    CMD_ERR("Error performing operation: "
> +		    "must specify a host name (-N) for move of m/s resource %s\n",
> +		    rsc_id);
> +
>  	} else if(current_uname != NULL
>  		  && (do_force || host_uname == NULL)) {
> -	    rc = move_resource(rsc_id, current_uname,
> +	    rc = move_resource(rsc_id, move_master, current_uname,
>  			       host_uname, cib_conn);
>  
> -			
>  	} else if(host_uname != NULL) {
>  	    rc = move_resource(
> -		rsc_id, NULL, host_uname, cib_conn);
> +		rsc_id, move_master, NULL, host_uname, cib_conn);
>  
>  	} else {
>  	    CMD_ERR("Resource %s not moved: "
> @@ -1536,7 +1592,7 @@
>  		    " specified.\n", rsc_id);
>  	    rc = cib_missing;
>  	}
> -		
> +
>      } else if(rsc_cmd == 'G') {
>  	if(rsc_id == NULL) {
>  	    CMD_ERR("Must supply a resource id with -r\n");

> # HG changeset patch
> # User Holger Teutsch <holger.teutsch at web.de>
> # Date 1300444053 -3600
> # Branch mig
> # Node ID ce9f161ae81858c0f30dea9e8a95dd118536a5aa
> # Parent  dac1a4eae844f0bd857951b1154a171c80c25772
> ui.py.in : Add support for move of Master role of a m/s resource
> 
> diff -r dac1a4eae844 -r ce9f161ae818 shell/modules/ui.py.in
> --- a/shell/modules/ui.py.in	Fri Mar 18 10:16:31 2011 +0100
> +++ b/shell/modules/ui.py.in	Fri Mar 18 11:27:33 2011 +0100
> @@ -847,8 +847,16 @@
>              return False
>          return set_deep_meta_attr("is-managed","false",rsc)
>      def migrate(self,cmd,*args):
> -        """usage: migrate <rsc> [<node>] [<lifetime>] [force]"""
> -        rsc = args[0]
> +        """usage: migrate <rsc>[:master] [<node>] [<lifetime>] [force]"""
> +        elem = args[0].split(':')
> +        rsc = elem[0]
> +        master = False
> +        if len(elem) > 1:
> +            master = elem[1]
> +            if master != "master":
> +                common_error("%s is invalid, specify 'master'" % master)
> +                return False
> +            master = True
>          if not is_name_sane(rsc):
>              return False
>          node = None
> @@ -888,6 +896,8 @@
>              opts = "%s --lifetime='%s'" % (opts,lifetime)
>          if force or user_prefs.get_force():
>              opts = "%s --force" % opts
> +        if master:
> +            opts = "%s --master" % opts
>          return ext_cmd(self.rsc_migrate % (rsc,opts)) == 0
>      def unmigrate(self,cmd,rsc):
>          "usage: unmigrate <rsc>"

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