[Sheepdog] [PATCH] sheep: support specifying the initial count of virtual nodes

[MORITA Kazutaka]

With this patch, you can set the weight of each node with the -v
option.

Example:

  $ ./sheep/sheep /store/0 -p 7000 -z 0 -v 1000
  $ ./sheep/sheep /store/1 -p 7001 -z 1 -v 2000
  $ ./sheep/sheep /store/2 -p 7002 -z 2 -v 3000
  $ ./collie/collie cluster format -c 1
  using backend simple store
  $ ./collie/collie node list
  M   Id   Host:Port         V-Nodes       Zone
  -    0   10.68.14.1:7000        1000          0
  -    1   10.68.14.1:7001        2000          1
  -    2   10.68.14.1:7002        3000          2
  $ ./collie/collie vdi create image 600M -P
  $ ./collie/collie node info
  Id      Size    Used    Use%
   0      188 GB  100 MB    0%
   1      188 GB  200 MB    0%
   2      188 GB  304 MB    0%
  Total   564 GB  604 MB    0%

  Total virtual image size  600 MB

If you specify zero to the number of virtual nodes, no data will not
be stored to the node.

Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
---
 sheep/group.c      |    4 ++--
 sheep/sheep.c      |   16 ++++++++++++++--
 sheep/sheep_priv.h |    2 +-
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/sheep/group.c b/sheep/group.c
index 1a212e3..dda468c 100644
--- a/sheep/group.c
+++ b/sheep/group.c
@@ -1382,7 +1382,7 @@ oom:
 	panic("failed to allocate memory for a confchg event\n");
 }
 
-int create_cluster(int port, int64_t zone)
+int create_cluster(int port, int64_t zone, int nr_vnodes)
 {
 	int ret;
 	struct cdrv_handlers handlers = {
@@ -1407,7 +1407,7 @@ int create_cluster(int port, int64_t zone)
 		return -1;
 
 	sys->this_node.port = port;
-	sys->this_node.nr_vnodes = SD_DEFAULT_VNODES;
+	sys->this_node.nr_vnodes = nr_vnodes;
 	if (zone == -1) {
 		/* use last 4 bytes as zone id */
 		uint8_t *b = sys->this_node.addr + 12;
diff --git a/sheep/sheep.c b/sheep/sheep.c
index 94b4a9e..b3b834b 100644
--- a/sheep/sheep.c
+++ b/sheep/sheep.c
@@ -36,12 +36,13 @@ static struct option const long_options[] = {
 	{"debug", no_argument, NULL, 'd'},
 	{"directio", no_argument, NULL, 'D'},
 	{"zone", required_argument, NULL, 'z'},
+	{"vnodes", required_argument, NULL, 'v'},
 	{"cluster", required_argument, NULL, 'c'},
 	{"help", no_argument, NULL, 'h'},
 	{NULL, 0, NULL, 0},
 };
 
-static const char *short_options = "p:fl:dDz:c:h";
+static const char *short_options = "p:fl:dDz:v:c:h";
 
 static void usage(int status)
 {
@@ -59,6 +60,7 @@ Options:\n\
   -d, --debug             include debug messages in the log\n\
   -D, --directio          use direct IO when accessing the object store\n\
   -z, --zone              specify the zone id\n\
+  -v, --vnodes            specify the number of virtual nodes\n\
   -c, --cluster           specify the cluster driver\n\
   -h, --help              display this help and exit\n\
 ", PACKAGE_VERSION, program_name);
@@ -92,6 +94,7 @@ int main(int argc, char **argv)
 	int log_level = SDOG_INFO;
 	char path[PATH_MAX];
 	int64_t zone = -1;
+	int nr_vnodes = SD_DEFAULT_VNODES;
 	char *p;
 	struct cluster_driver *cdrv;
 
@@ -139,6 +142,15 @@ int main(int argc, char **argv)
 			}
 			sys->this_node.zone = zone;
 			break;
+		case 'v':
+			nr_vnodes = strtol(optarg, &p, 10);
+			if (optarg == p || nr_vnodes < 0 || SD_MAX_VNODES < nr_vnodes) {
+				fprintf(stderr, "Invalid number of virtual nodes '%s': "
+					"must be an integer between 0 and %u\n",
+					optarg, SD_MAX_VNODES);
+				exit(1);
+			}
+			break;
 		case 'c':
 			sys->cdrv = find_cdrv(optarg);
 			if (!sys->cdrv) {
@@ -192,7 +204,7 @@ int main(int argc, char **argv)
 	if (ret)
 		exit(1);
 
-	ret = create_cluster(port, zone);
+	ret = create_cluster(port, zone, nr_vnodes);
 	if (ret) {
 		eprintf("failed to create sheepdog cluster\n");
 		exit(1);
diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
index 880bb74..db70c57 100644
--- a/sheep/sheep_priv.h
+++ b/sheep/sheep_priv.h
@@ -235,7 +235,7 @@ int is_access_local(struct sd_vnode *e, int nr_nodes,
 
 void resume_pending_requests(void);
 
-int create_cluster(int port, int64_t zone);
+int create_cluster(int port, int64_t zone, int nr_vnodes);
 int leave_cluster(void);
 
 void start_cpg_event_work(void);
-- 
1.7.2.5