cpg_overview(8) [centos man page]

CPG_OVERVIEW(8) 				    Corosync Cluster Engine Programmer's Manual 				   CPG_OVERVIEW(8)

NAME

       cpg_overview - CPG library overview

OVERVIEW

       The CPG library is delivered with the corosync project.	This library is used to create distributed applications that operate properly dur-
       ing cluster partitions, merges, and faults.

       The library provides a mechanism to:

       * handle abstraction for multiple instances of a CPG library in one application

       * join one or more groups

       * leave one or more groups

       * Deliver messages to members of that group

       * Deliver configuration changes

       * Iterate members of groups

SECURITY

       If encryption is enabled in corosync.conf, the CPG library will encrypt and authenticate message contents.  Applications must  run  as  the
       ais user to be validated by corosync on IPC connection, otherwise they will be unable to access the corosync services.

SEE ALSO

       cpg_overview(8),  cpg_initialize(3),  cpg_finalize(3),  cpg_fd_get(3),  cpg_dispatch(3),  cpg_join(3),  cpg_leave(3),  cpg_mcast_joined(3),
       cpg_model_initialize(3), cpg_membership_get(3), cpg_zcb_alloc(3), cpg_zcb_free(3),  cpg_zcb_mcast_joined(3),  cpg_context_get(3),  cpg_con-
       text_set(3), cpg_local_get(3), cpg_iteration_initialize(3), cpg_iteration_next(3), cpg_iteration_finalize(3)

corosync Man Page						     2009-4-15							   CPG_OVERVIEW(8)

CPG_MCAST_JOINED(3)				    Corosync Cluster Engine Programmer's Manual 			       CPG_MCAST_JOINED(3)

NAME

       cpg_mcast_joined - Multicasts to all groups joined to a handle

SYNOPSIS

       #include <sys/uio.h> #include <corosync/cpg.h>

       int cpg_mcast_joined(cpg_handle_t handle, cpg_guarantee_t guarantee, struct iovec *iovec, int iov_len);

DESCRIPTION

       The  cpg_mcast_joined  function	will  multicast a message to all the processes that have been joined with the cpg_join(3) function for the
       same group name.  Messages that are sent to any of the groups joined to the parameter handle will be delivered to all subscribed  processes
       in the system.

       The argument guarantee requests a delivery guarantee for the message to be sent.  The cpg_guarantee_t type is defined by:

	      typedef enum {
		      CPG_TYPE_UNORDERED,     /* not implemented */
		      CPG_TYPE_FIFO,	      /* same as agreed */
		      CPG_TYPE_AGREED,	      /* implemented */
		      CPG_TYPE_SAFE	      /* not implemented */
	      } cpg_guarantee_t;

       The meanings of the cpg_guarantee_t typedef are:

       CPG_TYPE_UNORDERED
	      Messages are guaranteed to be delivered, but with no particular order.  This mode is unimplemented in the CPG library.

       CPG_TYPE_FIFO
	      Messages	are  guaranteed  to  be  delivered  in	first  sent  first  delivery  order.  In fact, this guarantee is equivalent to the
	      CPG_TYPE_AGREED guarantee.

       CPG_TYPE_AGREED
	      All processors must agree on the order of delivery.  If a message is sent from two or more processes at about  the  same	time,  the
	      delivery will occur in the same order to all processes.

       CPG_TYPE_SAFE
	      All  processes must agree on the order of delivery.  Further all processes must have a copy of the message before any delivery takes
	      place.  This mode is unimplemented in the CPG library.

       The iovec argument describes the scatter/gather list which is used to transmit a message.  This is a iovec described by:

	      struct iovec
	      {
		      void *iov_base;	  /* Pointer to data.  */
		      unsigned int iov_len;	/* Length of data.  */
	      };

       The iov_len argument describes the number of entires in the iovec argument.

RETURN VALUE

       This call returns the CPG_OK value if successful, otherwise an error is returned.

ERRORS

       The errors are undocumented.

SEE ALSO

       cpg_overview(8),  cpg_initialize(3),  cpg_finalize(3),  cpg_fd_get(3),  cpg_dispatch(3),  cpg_join(3),  cpg_leave(3),  cpg_mcast_joined(3),
       cpg_membership_get(3) cpg_zcb_alloc(3) cpg_zcb_free(3) cpg_zcb_mcast_joined(3) cpg_context_get(3) cpg_context_set(3) cpg_local_get(3)

corosync Man Page						    3004-08-31						       CPG_MCAST_JOINED(3)