Pfs_nn_coord
/* $Id: pfs_nn_coord.x 420 2011-09-26 21:03:14Z gerd $ -*- -c -*- */
Coordination
Find the coordinator.
One of the name nodes is elected to be the coordinator at cluster startup time. Right now, all namenode requests have to go to the coordinator. (In the future, the other namenodes may be allowed to respond to certain read requests.)
#include "pfs_types.x"
#ifndef PFS_NN_COORD
#define PFS_NN_COORD
program Coordination {
version V1 {
null
void null(void) = 0;
find_coordinator
longstring_opt find_coordinator(longstring) = 1;Returns the current coordinator as host:port string. The Filesystem requests must be sent to the coordinator.
The arg is the clustername. If this node is not part of this cluster the RPC will return NULL.
find_namenodes
longstrings find_namenodes(longstring) = 2;Return all name nodes, including the coordinator and the slaves.
The arg is the clustername. If this node is not part of this cluster the RPC will return an empty array.
is_coordinator
bool is_coordinator(longstring) = 3;Whether this node is the coordinator
The arg is the clustername. If this node is not part of this cluster the RPC will return false.
clustername
longstring clustername(void) = 4;Returns the clustername
/* find_inodecaches: no longer needed. This functionality is now directly provided by Filesystem. */
local_identities
longstrings local_identities(longstring) = 6;Returns the identities of the data nodes running on the machine of the caller. Only available data nodes are returned. The arg is the clustername.
} = 1;
} = 0x8000e002;
#endif
