rebalancer: add logging of routes

This patch adds rebalancer routes' logging. The log file now
includes information about the source storage, the number of
buckets, and the destination storage where the buckets will
be moved.

Since the rebalancer service has changed logging of routes that
were sent, we change the `rebalancer/rebalancer.test.lua` and
`rebalancer/stress_add_remove_several_rs.test.lua` tests.

Part of #212

NO_DOC=bugfix

Author: mrForza

test/rebalancer/rebalancer.result

@@ -149,7 +149,7 @@ test_run:switch('box_1_a')
 vshard.storage.rebalancer_enable()
 ---
 ...
-wait_rebalancer_state("Rebalance routes are sent", test_run)
+wait_rebalancer_state("The following rebalancer routes were sent", test_run)
 ---
 ...
 wait_rebalancer_state('The cluster is balanced ok', test_run)
@@ -239,7 +239,7 @@ cfg.rebalancer_disbalance_threshold = 0.01
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)
 ---
 ...
-wait_rebalancer_state('Rebalance routes are sent', test_run)
+wait_rebalancer_state('The following rebalancer routes were sent', test_run)
 ---
 ...
 wait_rebalancer_state('The cluster is balanced ok', test_run)

test/rebalancer/rebalancer.test.lua

@@ -78,7 +78,7 @@ util.map_bucket_protection(test_run, {REPLICASET_1}, true)
 
 test_run:switch('box_1_a')
 vshard.storage.rebalancer_enable()
-wait_rebalancer_state("Rebalance routes are sent", test_run)
+wait_rebalancer_state("The following rebalancer routes were sent", test_run)
 
 wait_rebalancer_state('The cluster is balanced ok', test_run)
 _bucket.index.status:count({vshard.consts.BUCKET.ACTIVE})
@@ -118,7 +118,7 @@ _bucket.index.status:count({vshard.consts.BUCKET.ACTIVE})
 -- Return 1%.
 cfg.rebalancer_disbalance_threshold = 0.01
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)
-wait_rebalancer_state('Rebalance routes are sent', test_run)
+wait_rebalancer_state('The following rebalancer routes were sent', test_run)
 wait_rebalancer_state('The cluster is balanced ok', test_run)
 _bucket.index.status:count({vshard.consts.BUCKET.ACTIVE})
 _bucket.index.status:min({vshard.consts.BUCKET.ACTIVE})

test/rebalancer/stress_add_remove_several_rs.result

@@ -175,7 +175,7 @@ add_replicaset()
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)
 ---
 ...
-wait_rebalancer_state('Rebalance routes are sent', test_run)
+wait_rebalancer_state('The following rebalancer routes were sent', test_run)
 ---
 ...
 -- Now, add a second replicaset.
@@ -422,7 +422,7 @@ remove_second_replicaset_first_stage()
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)
 ---
 ...
-wait_rebalancer_state('Rebalance routes are sent', test_run)
+wait_rebalancer_state('The following rebalancer routes were sent', test_run)
 ---
 ...
 -- Rebalancing has been started - now remove second replicaset.

test/rebalancer/stress_add_remove_several_rs.test.lua

@@ -71,7 +71,7 @@ fiber.sleep(0.5)
 test_run:switch('box_1_a')
 add_replicaset()
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)
-wait_rebalancer_state('Rebalance routes are sent', test_run)
+wait_rebalancer_state('The following rebalancer routes were sent', test_run)
 
 -- Now, add a second replicaset.
 
@@ -153,7 +153,7 @@ fiber.sleep(0.5)
 test_run:switch('box_1_a')
 remove_second_replicaset_first_stage()
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)
-wait_rebalancer_state('Rebalance routes are sent', test_run)
+wait_rebalancer_state('The following rebalancer routes were sent', test_run)
 -- Rebalancing has been started - now remove second replicaset.
 remove_replicaset_first_stage()
 vshard.storage.cfg(cfg, util.name_to_uuid.box_1_a)

test/storage-luatest/storage_1_1_1_test.lua

@@ -200,3 +200,23 @@ rebalancer_recovery_group.test_no_logs_while_unsuccess_recovery = function(g)
     wait_for_bucket_is_transferred(g.replica_2_a, g.replica_1_a,
                                    hanged_bucket_id_2)
 end
+
+rebalancer_recovery_group.test_rebalancer_routes_logging = function(g)
+    local moved_bucket_from_2 = vtest.storage_first_bucket(g.replica_2_a)
+    start_bucket_move(g.replica_2_a, g.replica_1_a, moved_bucket_from_2)
+    local moved_bucket_from_3 = vtest.storage_first_bucket(g.replica_3_a)
+    start_bucket_move(g.replica_3_a, g.replica_1_a, moved_bucket_from_3)
+    t.helpers.retrying({timeout = 60}, function()
+        g.replica_1_a:exec(function() ivshard.storage.rebalancer_wakeup() end)
+        t.assert(g.replica_1_a:grep_log('Apply rebalancer routes with 1 ' ..
+                                        'workers'))
+    end)
+    local rebalancer_routes_msg = string.format(
+        "{\"%s\":{\"%s\":1,\"%s\":1}}", g.replica_1_a:replicaset_uuid(),
+        g.replica_3_a:replicaset_uuid(), g.replica_2_a:replicaset_uuid())
+    t.assert(g.replica_1_a:grep_log(rebalancer_routes_msg))
+    t.helpers.retrying({}, function()
+        g.replica_1_a:exec(function() ivshard.storage.rebalancer_wakeup() end)
+        g.replica_1_a:grep_log('The cluster is balanced ok.')
+    end)
+end

vshard/storage/init.lua

@@ -2909,8 +2909,9 @@ local function rebalancer_service_f(service, limiter)
                 goto continue
             end
         end
-        log.info('Rebalance routes are sent. Schedule next wakeup after '..
-                 '%f seconds', consts.REBALANCER_WORK_INTERVAL)
+        log.info('The following rebalancer routes were sent: %s. ' ..
+                 'Schedule next wakeup after %f seconds', json_encode(routes),
+                 consts.REBALANCER_WORK_INTERVAL)
         service:set_activity('idling')
         lfiber.testcancel()
         lfiber.sleep(consts.REBALANCER_WORK_INTERVAL)