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openmpi/ompi/mca/btl/usnic/btl_usnic_connectivity.h
Jeff Squyres e37c7af0fb usnic: update cclient/cagent to use unix domain sockets (not RML)
In preparation for moving the BTLs down to OPAL, discontinue the use
of the RML for connectivity client/agent communication.  Instead, use
local unix domain sockets in the job session directory (all
communication is between processes on the same server, so unix domain
sockets are fine).

This commit was SVN r31710.
2014-05-09 20:35:36 +00:00

249 строки
8.1 KiB
C

/*
* Copyright (c) 2014 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#ifndef OMPI_BTL_USNIC_CONNECTIVITY_H
#define OMPI_BTL_USNIC_CONNECTIVITY_H
#include "ompi_config.h"
#include <netinet/in.h>
#include "opal/util/show_help.h"
#include "ompi/runtime/mpiruntime.h"
#include "btl_usnic_util.h"
/**
* Agent-based service to verify UDP connectivity between two peers.
*
* Generally, it is a client-server pattern with three entities
* involved:
*
* 1. Agent thread: running in MPI process local rank 0
* 2. Client: running in the main application thread in every MPI process
* 3. RTE thread: running in every MPI process
*
* If enabled (via MCA param), the usnic module_init() will setup the
* client (and server on local rank 0). For each usnic module, Each
* client will send a request to the server (via local Unix domain
* socket) asking it to listen on its usnic interface. The agent will
* discard duplicates and setup a single UDP socket listener on the
* eth interface corresponding to each requested usnic interface. The
* agent returns the listening UDP port number to the client, and each
* client puts this UDP port number in their modex information.
*
* At the first send to a given MPI process peer, the client will send
* another request to the server asking it to verify connectivity to
* the peer (supplying the peer's UDP listener port number from the
* peer's modex info). Again, the agent will discard duplicates -- it
* will only verify connectivity to each peer's *server* once. The
* agent will send a short UDP message and a long UDP message
* (basically, the MTU-68 bytes -- see comment in btl_usnic_cagent.c
* for the reasons why) to the listening peer UDP port.
*
* When the peer agent gets PING messages, it sends short ACK control
* messages back to the sending agent. When the sending agent gets
* all ACKs back from the peer, it rules that connectivity is GOOD and
* no further action is taken. If the sending agent doesn't get one
* or both ACKs back in a timely fashion, it re-sends the PING(s) that
* wasn't(weren't) ACKed. Eventually if the sending agent re-sends
* too many times and does not get an ACK back, it gives up, displays
* and error, and aborts the MPI job.
*
* Note that the client/server interaction is intentionally quite
* primitive:
*
* 1. Client requests agent to listen on interface X. Server responds
* with UDP port number of listener.
*
* 2. Client requests ping check to peer Y. Client does not wait for
* the answer; the agent either verifies the connectivity successfully
* or aborts the job.
*
* All client/agent communication is via blocking calls to a local
* Unix domain socket.
*
* As mentioned above, the agent is smart about discarding duplicate
* ping requests from clients. Since a single agent serves all MPI
* processes on a given server, this cuts down on a lot of PING
* traffic.
*/
/*
* Forward declaration
*/
struct ompi_btl_usnic_module_t;
/** @internal
* This macro just makes the macros below a little easier to read.
*/
#define ABORT(msg) ompi_btl_usnic_util_abort((msg), __FILE__, __LINE__, 1)
/**
* Local IPC socket message types. This value is either sent or
* packed as the first field in each message to identify its type.
* Use a non-zero value as the first enum just as defensive
* programming (i.e., it's a slightly lower chance that an
* uninitialized message type would randomly match these values).
*/
enum {
CONNECTIVITY_AGENT_CMD_LISTEN = 17,
CONNECTIVITY_AGENT_CMD_PING,
CONNECTIVITY_AGENT_CMD_MAX
};
#define CONNECTIVITY_NODENAME_LEN 128
#define CONNECTIVITY_IFNAME_LEN 32
/*
* Unix domain socket name
*/
#define CONNECTIVITY_SOCK_NAME "btl-usnic-cagent-socket"
/*
* Magic token to ensure that client/server recognize each other
*/
#define CONNECTIVITY_MAGIC_TOKEN "-*-I am usNIC; hear me roar-*-"
/*
* Fields for the LISTEN command. This struct is sent down the IPC
* socket from the cclient to the cagent.
*/
typedef struct {
uint32_t ipv4_addr;
uint32_t cidrmask;
uint32_t mtu;
char nodename[CONNECTIVITY_NODENAME_LEN];
char if_name[CONNECTIVITY_IFNAME_LEN];
char usnic_name[CONNECTIVITY_IFNAME_LEN];
uint8_t mac[6];
} ompi_btl_usnic_connectivity_cmd_listen_t;
/*
* Command+fields for the reply to the LISTEN command. This struct is
* sent down the IPC socket from the cagent to the cclient.
*/
typedef struct {
int32_t cmd;
uint32_t ipv4_addr;
uint32_t udp_port;
} ompi_btl_usnic_connectivity_cmd_listen_reply_t;
/*
* Fields for the PING command. This struct is sent down the IPC
* socket from the cclient to the cagent.
*/
typedef struct {
uint32_t src_ipv4_addr;
uint32_t src_udp_port;
uint32_t dest_ipv4_addr;
uint32_t dest_cidrmask;
uint32_t dest_udp_port;
uint32_t mtu;
char dest_nodename[CONNECTIVITY_NODENAME_LEN];
uint8_t dest_mac[6];
} ompi_btl_usnic_connectivity_cmd_ping_t;
/**
* Startup the connectivity client.
*
* @returns OMPI_SUCCESS or an OMPI error code.
*
* It is safe to call this function even if the connectivity check is
* disabled; it will be a no-op in this case.
*/
int ompi_btl_usnic_connectivity_client_init(void);
/**
* Tell the agent to establsh a listening port on the given IP
* address.
*
* @params[in] module The module that is requesting the listen.
*
* @returns OMPI_SUCCESS or an OMPI error code.
*
* The module contains the local interface addressing information,
* which tells the agent one which interface to listen.
*
* This routine will request the new listen from the agent, and wait
* for the agent to reply with the UDP port that is being used/was
* created. The UDP listening port will then be stuffed in
* module->local_addr.connectivity_udp_port (i.e., data that will be
* sent in the modex).
*
* It is safe to call this function even if the connectivity check is
* disabled; it will be a no-op in this case.
*/
int ompi_btl_usnic_connectivity_listen(struct ompi_btl_usnic_module_t *module);
/**
* Tell the agent to ping a specific IP address and UDP port number
* with a specific message size.
*
* @param[in] src_ipv4_addr The source module IPv4 address
* @param[in] src_port The source module listening UDP port
* @param[in] dest_ipv4_addr The destination IPv4 address
* @param[in] dest_cidrmask The destination CIDR mask
* @param[in] dest_port The destination UDP port
* @param[in] dest_mac The destination MAC address
* @param[in] dest_nodename The destination server name
* @param[in] mtu The max ping message size to send
*
* @returns OMPI_SUCCESS or an OMPI error code.
*
* Note that several of the above parameters are only passed so that
* they can be used in a complete/helpful error message, if necessary.
*
* This function does not wait for a reply from the agent; it assumes
* the agent will successfully ping the remote peer or will abort the
* MPI job if the pinging fails.
*
* It is safe to call this function even if the connectivity check is
* disabled; it will be a no-op in this case.
*/
int ompi_btl_usnic_connectivity_ping(uint32_t src_ipv4_addr, int src_port,
uint32_t dest_ipv4_addr,
uint32_t dest_cidrmask, int dest_port,
uint8_t *dest_mac, char *dest_nodename,
size_t mtu);
/**
* Shut down the connectivity service client.
*
* @returns OMPI_SUCCESS or an OMPI error code.
*
* It is safe to call this function even if the connectivity check is
* disabled; it will be a no-op in this case.
*/
int ompi_btl_usnic_connectivity_client_finalize(void);
/**
* Startup the connectivity agent.
*
* @returns OMPI_SUCCESS or an OMPI error code.
*
* This function will be a no-op if this process is not the local rank
* 0.
*/
int ompi_btl_usnic_connectivity_agent_init(void);
/**
* Shut down the connectivity agent
*
* @returns OMPI_SUCCESS or an OMPI error code.
*
* This function will be a no-op if this process is not the local rank
* 0.
*/
int ompi_btl_usnic_connectivity_agent_finalize(void);
#endif /* OMPI_BTL_USNIC_CONNECITIVITY_H */