X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/8c354c48ec90c997cc7213ce96ca97d882934166..15c81e44412415173de220954a453019c68714cd:/include/amok/bandwidth.h
diff --git a/include/amok/bandwidth.h b/include/amok/bandwidth.h
index 22da712d39..787a6c0406 100644
--- a/include/amok/bandwidth.h
+++ b/include/amok/bandwidth.h
@@ -1,8 +1,7 @@
-/* $Id$ */
-
/* amok_bandwidth - Bandwidth test facilities */
-/* Copyright (c) 2004 Martin Quinson. All rights reserved. */
+/* Copyright (c) 2004, 2005, 2006, 2007, 2009, 2010. The SimGrid Team.
+ * All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
@@ -10,95 +9,132 @@
#ifndef AMOK_BANDWIDTH_H
#define AMOK_BANDWIDTH_H
-#include "amok/base.h"
-
-/* module handling */
-
-void amok_bw_init(void);
-void amok_bw_exit(void);
-
-
-
-/* ***************************************************************************
- * Bandwidth tests
- * ***************************************************************************/
-/**
- * amok_bw_test:
- * @peer: A (regular) socket at which the the host with which we should conduct the experiment can be contacted
- * @buf_size: Size of the socket buffer
- * @exp_size: Total size of data sent across the network
- * @msg_size: Size of each message sent. Ie, (@expSize % @msgSize) messages will be sent.
- * @sec: where the result (in seconds) should be stored.
- * @bw: observed Bandwidth (in Mb/s)
+/** \addtogroup AMOK_bw
+ * \brief Test the bandwidth between two nodes
*
- * Conduct a bandwidth test from the local process to the given peer.
- * This call is blocking until the end of the experiment.
- */
-xbt_error_t amok_bw_test(gras_socket_t peer,
- unsigned int buf_size,unsigned int exp_size,unsigned int msg_size,
- /*OUT*/ double *sec, double *bw);
-
-#if 0
-/**
- * grasbw_request:
- * @from_name: Name of the host we are asking to do a experiment with (to_name:to_port)
- * @from_port: port on which the process we are asking for an experiment is listening for message
- * @to_name: Name of the host with which we should conduct the experiment
- * @to_port: port on which the peer process is listening (for message, do not
- * give a raw socket here. The needed raw socket will be negociated between
- * the peers)
- * @bufSize: Size of the socket buffer
- * @expSize: Total size of data sent across the network
- * @msgSize: Size of each message sent. Ie, (@expSize % @msgSize) messages will be sent.
- * @sec: where the result (in seconds) should be stored.
- * @bw: observed Bandwidth (in Mb/s)
+ * This module allows you to retrieve the bandwidth between to arbitrary hosts
+ * and saturating the links leading to them, provided that they run some GRAS
+ * process which initialized this module.
+ *
+ * \htmlonly Bandwidth measurement
\endhtmlonly
+ *
+ * Retrieving the bandwidth is usually done by active measurment: one send
+ * a packet of known size, time how long it needs to go back and forth,
+ * and you get the bandwidth in Kb/s available on the wire.
+ *
+ * This is not as easy as it first seems to do so in GRAS. The first issue
+ * is that GRAS messages can get buffered, or the receiver cannot be
+ * waiting for the message when it arrives. This results in extra delays
+ * impacting the measurement quality. You thus have to setup a rendez-vous
+ * protocol. The second issue is that GRAS message do have an header, so
+ * figuring out their size is not trivial. Moreover, they get converted
+ * when the sender and receiver processor architecture are different,
+ * inducing extra delays. For this, GRAS provide the so-called measurement
+ * sockets. On them, you can send raw data which is not converted (see
+ * \ref GRAS_sock_meas).
+ *
+ * Solving all these problems is quite error prone and anoying, so we
+ * implemented this in the current module so that you don't have to do it
+ * yourself. The API is very simple. Use amok_bw_test() to get the BW
+ * between the local host and the specified peer, or amok_bw_request() to
+ * get the BW between two remote hosts. The elapsed time, as long as the
+ * achieved bandwidth is returned in the last arguments of the functions.
+ *
+ * All sizes are in bytes. The \a buf_size is the size of the buffer
+ * (this is a socket parameter set automatically). The \a exp_size is the
+ * amount of data to send during an experiment. \a msg_size is the size
+ * of each message sent. These values allow you to study phenomenon such
+ * as TCP slow start (which are not correctly modelized by \ref SURF_API,
+ * yet). They are mimicked from the NWS API, and default values could be
+ * buf_size=32k, msg_size=16k and exp_size=64k. That means that the
+ * socket will be prepared to accept 32k in its buffer and then four
+ * messages of 16k will be sent (so that the total amount of data equals
+ * 64k). Of course, you can use other values if you want to.
+ *
+ * \htmlonly
+ * 
+ * Fig 1: AMOK bandwidth measurement protocol.
+ * Link saturation
+ * \endhtmlonly
+ *
+ * You sometimes want to try saturating some link during the network
+ * related experiments (at least, we did ;). This also can turn quite
+ * untrivial to do, unless you use this great module. You can either ask
+ * for the saturation between the current host and a distant one with
+ * amok_bw_saturate_begin() or between two distant hosts with
+ * amok_bw_saturate_start(). In any case, remember that gras actors
+ * (processes) are not interruptible. It means that an actor you
+ * instructed to participate to a link saturation experiment will not do
+ * anything else until it is to its end (either because the asked duration
+ * was done or because someone used amok_bw_saturate_stop() on the emitter
+ * end of the experiment).
+ *
+ * The following figure depicts the used protocol. Note that any
+ * handshaking messages internal messages are omitted for sake of
+ * simplicity. In this example, the experiment ends before the planned
+ * experiment duration is over because one host use the
+ * amok_bw_saturate_stop() function, but things are not really different
+ * if the experiment stops alone. Also, it is not mandatory that the host
+ * calling amok_bw_saturate_stop() is the same than the one which called
+ * amok_bw_saturate_start(), despite what is depicted here.
+ *
+ * \htmlonly
+ * 
+ * Fig 2: AMOK link saturation protocol.
+ * \endhtmlonly
*
- * Conduct a bandwidth test from the process from_host:from_port to to_host:to_port.
- * This call is blocking until the end of the experiment.
+ * @{
*/
-xbt_error_t grasbw_request(const char* from_name,unsigned int from_port,
- const char* to_name,unsigned int to_port,
- unsigned int bufSize,unsigned int expSize,unsigned int msgSize,
- /*OUT*/ double *sec, double*bw);
+/* module handling */
+
+XBT_PUBLIC(void) amok_bw_init(void);
+XBT_PUBLIC(void) amok_bw_exit(void);
+
+XBT_PUBLIC(void) amok_bw_test(gras_socket_t peer,
+ unsigned long int buf_size,
+ unsigned long int msg_size,
+ unsigned long int msg_amount,
+ double min_duration,
+ /*OUT*/ double *sec, double *bw);
+
+XBT_PUBLIC(void) amok_bw_request(const char *from_name,
+ unsigned int from_port,
+ const char *to_name, unsigned int to_port,
+ unsigned long int buf_size,
+ unsigned long int msg_size,
+ unsigned long int msg_amount,
+ double min_duration, /*OUT*/ double *sec,
+ double *bw);
+
+XBT_PUBLIC(double *) amok_bw_matrix(xbt_dynar_t hosts, /* dynar of xbt_host_t */
+ int buf_size_bw, int msg_size_bw,
+ int msg_amount_bw,
+ double min_duration);
/* ***************************************************************************
* Link saturation
* ***************************************************************************/
-/**
- * grasbw_saturate_start:
- * @from_name: Name of the host we are asking to do a experiment with (to_name:to_port)
- * @from_port: port on which the process we are asking for an experiment is listening
- * (for message, do not give a raw socket here. The needed raw socket will be negociated
- * between the peers)
- * @to_name: Name of the host with which we should conduct the experiment
- * @to_port: port on which the peer process is listening for message
- * @msgSize: Size of each message sent.
- * @timeout: How long in maximum should be the saturation.
- *
- * Ask the process 'from_name:from_port' to start to saturate the link between itself
- * and to_name:to_name.
- */
-xbt_error_t grasbw_saturate_start(const char* from_name,unsigned int from_port,
- const char* to_name,unsigned int to_port,
- unsigned int msgSize, unsigned int timeout);
-
-/**
- * grasbw_saturate_stop:
- * @from_name: Name of the host we are asking to do a experiment with (to_name:to_port)
- * @from_port: port on which the process we are asking for an experiment is listening
- * (for message, do not give a raw socket here. The needed raw socket will be negociated
- * between the peers)
- * @to_name: Name of the host with which we should conduct the experiment
- * @to_port: port on which the peer process is listening for message
- *
- * Ask the process 'from_name:from_port' to stop saturating the link between itself
- * and to_name:to_name.
- */
-xbt_error_t grasbw_saturate_stop(const char* from_name,unsigned int from_port,
- const char* to_name,unsigned int to_port);
+XBT_PUBLIC(void) amok_bw_saturate_start(const char *from_name,
+ unsigned int from_port,
+ const char *to_name,
+ unsigned int to_port,
+ unsigned int msg_size,
+ double duration);
+
+XBT_PUBLIC(void) amok_bw_saturate_begin(const char *to_name,
+ unsigned int to_port,
+ unsigned int msg_size,
+ double duration,
+ /*out */ double *elapsed,
+ double *bw);
+
+XBT_PUBLIC(void) amok_bw_saturate_stop(const char *from_name,
+ unsigned int from_port,
+ /*out */ double *time, double *bw);
+
+/** @} */
-#endif /* if 0 */
-#endif /* AMOK_BANDWIDTH_H */
+#endif /* AMOK_BANDWIDTH_H */