[PATCH 6 of 7 V4] tools/xl: Remus - Network buffering cmdline switch

[Shriram Rajagopalan <rshriram@cs.ubc.ca>]

# HG changeset patch
# User Shriram Rajagopalan <rshriram@cs.ubc.ca>
# Date 1384492678 28800
# Node ID 6a2a1bfffc666d5c7aaaa3532c709f2e38a86d05
# Parent  8e5366a6cd958c00a9b7a726c149a552a02a7af6
tools/xl: Remus - Network buffering cmdline switch

Command line switch to 'xl remus' command, to enable network buffering.
Pass on this flag to libxl so that it can act accordingly.
Also update man pages to reflect the addition of a new option to
'xl remus' command.

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>

diff -r 8e5366a6cd95 -r 6a2a1bfffc66 docs/man/xl.conf.pod.5
--- a/docs/man/xl.conf.pod.5	Thu Nov 14 21:17:57 2013 -0800
+++ b/docs/man/xl.conf.pod.5	Thu Nov 14 21:17:58 2013 -0800
@@ -105,6 +105,12 @@ Configures the default gateway device to
 
 Default: C<None>
 
+=item B<remus.default.netbufscript="PATH">
+
+Configures the default script used by Remus to setup network buffering.
+
+Default: C</etc/xen/scripts/remus-netbuf-setup>
+
 =item B<output_format="json|sxp">
 
 Configures the default output format used by xl when printing "machine
diff -r 8e5366a6cd95 -r 6a2a1bfffc66 docs/man/xl.pod.1
--- a/docs/man/xl.pod.1	Thu Nov 14 21:17:57 2013 -0800
+++ b/docs/man/xl.pod.1	Thu Nov 14 21:17:58 2013 -0800
@@ -398,8 +398,7 @@ Print huge (!) amount of debug during th
 Enable Remus HA for domain. By default B<xl> relies on ssh as a transport
 mechanism between the two hosts.
 
-N.B: Remus support in xl is still in experimental (proof-of-concept) phase.
-     There is no support for network or disk buffering at the moment.
+N.B: There is no support for disk buffering at the moment.
 
 B<OPTIONS>
 
@@ -418,6 +417,18 @@ Generally useful for debugging.
 
 Disable memory checkpoint compression.
 
+=item B<-n>
+
+Enable network output buffering.  The default script used to configure
+network buffering is /etc/xen/scripts/remus-netbuf-setup. If you wish to
+use a custom script, use the I<-N> option or set the global variable
+I<remus.default.netbufscript> in /etc/xen/xl.conf to point to your script.
+
+=item B<-N> I<netbufscript>
+
+Use <netbufscript> to setup network buffering instead of the instead of
+the default (/etc/xen/scripts/remus-netbuf-setup).
+
 =item B<-s> I<sshcommand>
 
 Use <sshcommand> instead of ssh.  String will be passed to sh.
diff -r 8e5366a6cd95 -r 6a2a1bfffc66 tools/libxl/xl.c
--- a/tools/libxl/xl.c	Thu Nov 14 21:17:57 2013 -0800
+++ b/tools/libxl/xl.c	Thu Nov 14 21:17:58 2013 -0800
@@ -46,6 +46,7 @@ char *default_vifscript = NULL;
 char *default_bridge = NULL;
 char *default_gatewaydev = NULL;
 char *default_vifbackend = NULL;
+char *default_remus_netbufscript = NULL;
 enum output_format default_output_format = OUTPUT_FORMAT_JSON;
 int claim_mode = 1;
 
@@ -177,6 +178,9 @@ static void parse_global_config(const ch
     if (!xlu_cfg_get_long (config, "claim_mode", &l, 0))
         claim_mode = l;
 
+    xlu_cfg_replace_string (config, "remus.default.netbufscript",
+                            &default_remus_netbufscript, 0);
+
     xlu_cfg_destroy(config);
 }
 
diff -r 8e5366a6cd95 -r 6a2a1bfffc66 tools/libxl/xl.h
--- a/tools/libxl/xl.h	Thu Nov 14 21:17:57 2013 -0800
+++ b/tools/libxl/xl.h	Thu Nov 14 21:17:58 2013 -0800
@@ -152,6 +152,7 @@ extern char *default_vifscript;
 extern char *default_bridge;
 extern char *default_gatewaydev;
 extern char *default_vifbackend;
+extern char *default_remus_netbufscript;
 extern char *blkdev_start;
 
 enum output_format {
diff -r 8e5366a6cd95 -r 6a2a1bfffc66 tools/libxl/xl_cmdimpl.c
--- a/tools/libxl/xl_cmdimpl.c	Thu Nov 14 21:17:57 2013 -0800
+++ b/tools/libxl/xl_cmdimpl.c	Thu Nov 14 21:17:58 2013 -0800
@@ -7115,8 +7115,9 @@ int main_remus(int argc, char **argv)
     r_info.interval = 200;
     r_info.blackhole = 0;
     r_info.compression = 1;
-
-    SWITCH_FOREACH_OPT(opt, "bui:s:e", NULL, "remus", 2) {
+    r_info.netbuf = 0;
+
+    SWITCH_FOREACH_OPT(opt, "buni:s:N:e", NULL, "remus", 2) {
     case 'i':
         r_info.interval = atoi(optarg);
         break;
@@ -7126,6 +7127,12 @@ int main_remus(int argc, char **argv)
     case 'u':
         r_info.compression = 0;
         break;
+    case 'n':
+        r_info.netbuf = 1;
+        break;
+    case 'N':
+        r_info.netbufscript = optarg;
+        break;
     case 's':
         ssh_command = optarg;
         break;
@@ -7137,6 +7144,9 @@ int main_remus(int argc, char **argv)
     domid = find_domain(argv[optind]);
     host = argv[optind + 1];
 
+    if(!r_info.netbufscript)
+        r_info.netbufscript = default_remus_netbufscript;
+
     if (r_info.blackhole) {
         send_fd = open("/dev/null", O_RDWR, 0644);
         if (send_fd < 0) {
@@ -7174,13 +7184,10 @@ int main_remus(int argc, char **argv)
     /* Point of no return */
     rc = libxl_domain_remus_start(ctx, &r_info, domid, send_fd, recv_fd, 0);
 
-    /* If we are here, it means backup has failed/domain suspend failed.
-     * Try to resume the domain and exit gracefully.
+    /* If we are here, it means remus setup/domain suspend/backup has
+     * failed. Try to resume the domain and exit gracefully.
      * TODO: Split-Brain check.
      */
-    fprintf(stderr, "remus sender: libxl_domain_suspend failed"
-            " (rc=%d)\n", rc);
-
     if (rc == ERROR_GUEST_TIMEDOUT)
         fprintf(stderr, "Failed to suspend domain at primary.\n");
     else {
diff -r 8e5366a6cd95 -r 6a2a1bfffc66 tools/libxl/xl_cmdtable.c
--- a/tools/libxl/xl_cmdtable.c	Thu Nov 14 21:17:57 2013 -0800
+++ b/tools/libxl/xl_cmdtable.c	Thu Nov 14 21:17:58 2013 -0800
@@ -481,6 +481,9 @@ struct cmd_spec cmd_table[] = {
       "-i MS                   Checkpoint domain memory every MS milliseconds (def. 200ms).\n"
       "-b                      Replicate memory checkpoints to /dev/null (blackhole)\n"
       "-u                      Disable memory checkpoint compression.\n"
+      "-n                      Enable network output buffering.\n"
+      "-N <netbufscript>       Use netbufscript to setup network buffering instead of the\n"
+      "                        instead of the default (/etc/xen/scripts/remus-netbuf-setup).\n"
       "-s <sshcommand>         Use <sshcommand> instead of ssh.  String will be passed\n"
       "                        to sh. If empty, run <host> instead of \n"
       "                        ssh <host> xl migrate-receive -r [-e]\n"