glusterd: CLI commands to create and manage tiered volumes.

A tiered volume is a normal volume with some number of new bricks
representing "hot" storage. The "hot" bricks can be attached or
detached dynamically to a normal volume. When this happens, a new graph
is constructed. The root of the new graph is an instance of the tier
translator. One subvolume of the tier translator leads to the old volume,
and another leads to the new hot bricks.

attach-tier <VOLNAME> [<replica> <COUNT>] <NEW-BRICK> ... [force]

volume detach-tier <VOLNAME> [replica <COUNT>] <BRICK>
... <start|stop|status|commit|force>

gluster volume rebalance <volume> tier start

gluster volume rebalance <volume> tier stop

gluster volume rebalance <volume> tier status

The "tier start" CLI command starts a server side daemon. The daemon
initiates file level migration based on caching policies. The daemon's
status can be monitored and stopped.

Note development on the "tier status" command is incomplete. It will be
added in a subsequent patch.

When the "hot" storage is detached, the tier translator is removed
from the graph and the tiered volume reverts to its original state as
described in the volume's info file.

For more background and design see the feature page [1].

[1]
http://www.gluster.org/community/documentation/index.php/Features/data-classification

Change-Id: Ic8042ce37327b850b9e199236e5be3dae95d2472
BUG: 1194753
Signed-off-by: Dan Lambright <dlambrig@redhat.com>
Reviewed-on: http://review.gluster.org/9753
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index 5b2b14503ae..5696229572d 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -812,6 +812,63 @@ out:
                         " for volume %s", volinfo->volname);
         return ret;
 }
+
+int32_t
+glusterd_volume_write_tier_details (int fd, glusterd_volinfo_t *volinfo)
+{
+        int32_t      ret            = -1;
+        char         buf[PATH_MAX]  = "";
+
+        if (volinfo->type != GF_CLUSTER_TYPE_TIER) {
+                ret = 0;
+                goto out;
+        }
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->tier_info.cold_brick_count);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_COLD_COUNT, buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d",
+                  volinfo->tier_info.cold_replica_count);
+        ret = gf_store_save_value (fd,
+                                   GLUSTERD_STORE_KEY_COLD_REPLICA_COUNT,
+                                   buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->tier_info.cold_disperse_count);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_COLD_DISPERSE_COUNT,
+                                   buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->tier_info.hot_brick_count);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_HOT_COUNT,
+                                   buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->tier_info.hot_replica_count);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_HOT_REPLICA_COUNT,
+                                   buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->tier_info.hot_type);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_HOT_TYPE, buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->tier_info.cold_type);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_COLD_TYPE, buf);
+        if (ret)
+                goto out;
+
+ out:
+        return ret;
+}
+
 int32_t
 glusterd_volume_exclude_options_write (int fd, glusterd_volinfo_t *volinfo)
 {
@@ -917,6 +974,8 @@ glusterd_volume_exclude_options_write (int fd, glusterd_volinfo_t *volinfo)
                         goto out;
         }
 
+        ret = glusterd_volume_write_tier_details (fd, volinfo);
+
         ret = glusterd_volume_write_snap_details (fd, volinfo);
 
 out:
@@ -2725,6 +2784,27 @@ glusterd_store_update_volinfo (glusterd_volinfo_t *volinfo)
                                 strlen (GLUSTERD_STORE_KEY_PARENT_VOLNAME))) {
                         strncpy (volinfo->parent_volname, value,
                                  sizeof(volinfo->parent_volname) - 1);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_COLD_COUNT,
+                                     strlen (key))) {
+                        volinfo->tier_info.cold_brick_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_COLD_REPLICA_COUNT,
+                                     strlen (key))) {
+                        volinfo->tier_info.cold_replica_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_COLD_DISPERSE_COUNT,
+                                     strlen (key))) {
+                        volinfo->tier_info.cold_disperse_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_HOT_COUNT,
+                                     strlen (key))) {
+                        volinfo->tier_info.cold_brick_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_HOT_REPLICA_COUNT,
+                                     strlen (key))) {
+                        volinfo->tier_info.cold_replica_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_HOT_TYPE,
+                                     strlen (key))) {
+                        volinfo->tier_info.hot_type = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_COLD_TYPE,
+                                     strlen (key))) {
+                        volinfo->tier_info.cold_type = atoi (value);
                 } else {
 
                         if (is_key_glusterd_hooks_friendly (key)) {
@@ -2809,6 +2889,9 @@ glusterd_store_update_volinfo (glusterd_volinfo_t *volinfo)
                                 GF_ASSERT (volinfo->redundancy_count > 0);
                         break;
 
+                        case GF_CLUSTER_TYPE_TIER:
+                        break;
+
                         default:
                                 GF_ASSERT (0);
                         break;