abstract: fix switch in_replicaset value

Execution of non-yielding DDL statements in transactions has been
allowed only since Tarantool 2.2.1 [1]. We should avoid using DDL
statements in transactions for older versions.

1. tarantool/tarantool@f266559

Closes #185

Author: oleg-jukovec

queue/abstract.lua

@@ -11,6 +11,10 @@ local qc       = require('queue.compat')
 local num_type = qc.num_type
 local str_type = qc.str_type
 
+-- since:
+-- https://github.com/tarantool/tarantool/commit/f266559b167b4643c377724eebde9651877d6cc9
+local ddl_txn_supported = qc.check_version({2, 2, 1})
+
 -- The term "queue session" has been added to the queue. One "queue session"
 -- can include many connections (box.session). For clarity, the box.session
 -- will be referred to as connection below.
@@ -668,13 +672,23 @@ local function switch_in_replicaset(replicaset_mode)
         box.space._queue_taken_2_mgr:insert(tuple)
     end
 
-    box.space._queue_taken_2:drop()
-    box.space._queue_taken_2_mgr:rename('_queue_taken_2')
+    if ddl_txn_supported then
+		-- We can do it inside a transaction.
+        box.space._queue_taken_2:drop()
+        box.space._queue_taken_2_mgr:rename('_queue_taken_2')
+    end
 
     local status, err = pcall(box.commit)
     if not status then
         error(('Error migrate _queue_taken_2: %s'):format(tostring(err)))
     end
+
+    if not ddl_txn_supported then
+		-- Do it outside a transaction becase DDL does not support
+		-- multi-statement transactions.
+        box.space._queue_taken_2:drop()
+        box.space._queue_taken_2_mgr:rename('_queue_taken_2')
+    end
 end
 
 -- create or join infrastructure

queue/abstract/queue_session.lua

@@ -7,6 +7,9 @@ local qc       = require('queue.compat')
 local num_type = qc.num_type
 local str_type = qc.str_type
 
+-- since:
+-- https://github.com/tarantool/tarantool/commit/f266559b167b4643c377724eebde9651877d6cc9
+local ddl_txn_supported = qc.check_version({2, 2, 1})
 
 local queue_session = {}
 
@@ -62,13 +65,23 @@ local function switch_in_replicaset(replicaset_mode)
         box.space._queue_shared_sessions_mgr:insert(tuple)
     end
 
-    box.space._queue_shared_sessions:drop()
-    box.space._queue_shared_sessions_mgr:rename('_queue_shared_sessions')
+    if ddl_txn_supported then
+		-- We can do it inside a transaction.
+        box.space._queue_shared_sessions:drop()
+        box.space._queue_shared_sessions_mgr:rename('_queue_shared_sessions')
+    end
 
     local status, err = pcall(box.commit)
     if not status then
         error(('Error migrate _queue_shared_sessions: %s'):format(tostring(err)))
     end
+
+    if not ddl_txn_supported then
+		-- Do it outside a transaction becase DDL does not support
+		-- multi-statement transactions.
+        box.space._queue_shared_sessions:drop()
+        box.space._queue_shared_sessions_mgr:rename('_queue_shared_sessions')
+    end
 end
 
 --- Create everything that's needed to work with "shared" sessions.

t/200-master-replica.t

@@ -21,7 +21,7 @@ end
 -- Replica connection handler.
 local conn = {}
 
-test:plan(8)
+test:plan(7)
 
 test:test('Check master-replica setup', function(test)
     test:plan(8)
@@ -46,19 +46,6 @@ test:test('Check master-replica setup', function(test)
     test:ok(tube, 'test tube created')
 end)
 
-test:test('Check error create temporary tube', function(test)
-    test:plan(2)
-    local engine = os.getenv('ENGINE') or 'memtx'
-
-    queue.cfg{ttr = 0.5, in_replicaset = true}
-    local opts = {temporary = true, engine = engine}
-    local status, err = pcall(queue.create_tube, 'test', 'fifo', opts)
-    test:is(status, false, 'test tube should not be created')
-    local founded = string.find(err,
-        'Cannot create temporary tube in replicaset mode')
-    test:ok(founded, 'unexpected error')
-end)
-
 test:test('Check queue state switching', function(test)
     test:plan(4)
     box.cfg{read_only = true}

t/210-cfg-in-replicaset.t

@@ -0,0 +1,43 @@
+#!/usr/bin/env tarantool
+
+local test  = require('tap').test('')
+local queue = require('queue')
+
+rawset(_G, 'queue', require('queue'))
+
+test:plan(2)
+
+test:test('Check in_replicaset switches', function(test)
+    test:plan(4)
+    local engine = os.getenv('ENGINE') or 'memtx'
+
+    box.cfg({})
+
+    local status, err = pcall(queue.cfg, {in_replicaset = true})
+    test:ok(status, 'in_replicaset = true switched')
+    local status, _ = pcall(queue.cfg, {in_replicaset = false})
+    test:ok(status, 'in_replicaset = false switched')
+    local status, _ = pcall(queue.cfg, {in_replicaset = true})
+    test:ok(status, 'in_replicaset = true switched')
+    local status, _ = pcall(queue.cfg, {in_replicaset = false})
+    test:ok(status, 'in_replicaset = false switched')
+end)
+
+test:test('Check error create temporary tube', function(test)
+    test:plan(2)
+    local engine = os.getenv('ENGINE') or 'memtx'
+
+    box.cfg({})
+
+    queue.cfg{ttr = 0.5, in_replicaset = true}
+    local opts = {temporary = true, engine = engine}
+    local status, err = pcall(queue.create_tube, 'test', 'fifo', opts)
+    test:is(status, false, 'test tube should not be created')
+    local founded = string.find(err,
+        'Cannot create temporary tube in replicaset mode')
+    test:ok(founded, 'unexpected error')
+end)
+
+rawset(_G, 'queue', nil)
+os.exit(test:check() and 0 or 1)
+-- vim: set ft=lua :