Merge branch '2.3' into 2.4

BUILD/mdbci/create_full_repo.sh

@@ -0,0 +1,106 @@
+#!/bin/bash
+
+# $box - Vagrant box to be used for build
+
+# $target - name of repository to put results
+
+# $cmake_flags - cmake flags to be used in the build
+
+# $MDBCI_VM_PATH - path to the MDBCI virtual machies directory
+
+# $source - reference to the point in the source code repository
+
+# $do_not_destroy_vm - if "yes" VM stays alive after the build
+
+# $try_already_running - if "yes" already running VM will be used for build
+
+# $gpg_keys_path - path to the directory containing GPG keys for repo signing
+# directory have to contain only one file *.public and only one *.private
+
+set -x
+
+# read the name of build scripts directory
+export script_dir="$(dirname $(readlink -f $0))"
+
+# load all needed variables
+. ${script_dir}/set_build_variables.sh
+
+export platform=`${mdbci_dir}/mdbci show boxinfo --box-name=$box --field='platform' --silent`
+export platform_version=`${mdbci_dir}/mdbci show boxinfo --box-name=$box --field='platform_version' --silent`
+export dist_sfx="$platform"."$platform_version"
+
+# prerare VM
+export provider=`${mdbci_dir}/mdbci show provider $box --silent 2> /dev/null`
+export name="$box-${JOB_NAME}-${BUILD_NUMBER}"
+export name=`echo $name | sed "s|/|-|g"`
+
+
+# destroying existing box
+if [ -d "$MDBCI_VM_PATH/${name}" ]; then
+	${mdbci_dir}/mdbci destroy $name
+fi
+
+  eval "cat <<EOF
+$(<${script_dir}/templates/build.json.template)
+" 2> /dev/null > $MDBCI_VM_PATH/${name}.json
+
+# starting VM for build
+echo "Generating build VM template"
+${mdbci_dir}/mdbci --override --template $MDBCI_VM_PATH/$name.json generate $name
+echo "starting VM for build"
+${mdbci_dir}/mdbci up --attempts=1 $name
+if [ $? != 0 ] ; then
+	echo "Error starting VM"
+	exit 1
+fi
+echo "copying public keys to VM"
+cp  ~/build-scripts/team_keys .
+${mdbci_dir}/mdbci public_keys --key team_keys --silent $name
+
+
+echo "Get VM info"
+export sshuser=`${mdbci_dir}/mdbci ssh --command 'whoami' --silent $name/build 2> /dev/null | tr -d '\r'`
+export IP=`${mdbci_dir}/mdbci show network $name/build --silent 2> /dev/null`
+export sshkey=`${mdbci_dir}/mdbci show keyfile $name/build --silent 2> /dev/null | sed 's/"//g'`
+export scpopt="-i $sshkey -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o ConnectTimeout=120 "
+export sshopt="$scpopt $sshuser@$IP"
+
+rm -rf $pre_repo_dir/$target/$box
+mkdir -p $pre_repo_dir/$target/SRC
+mkdir -p $pre_repo_dir/$target/$box
+
+export work_dir="MaxScale"
+export orig_image=$box
+
+ssh $sshopt "sudo rm -rf $work_dir"
+echo "copying stuff to $image machine"
+ssh $sshopt "mkdir -p $work_dir"
+
+rsync -avz --delete -e "ssh $scpopt" ${script_dir}/../../ $sshuser@$IP:./$work_dir/
+if [ $? -ne 0 ] ; then
+  echo "Error copying stuff to $box machine"
+  exit 2
+fi
+
+ssh $sshopt ./MaxScale/BUILD/install_build_deps.sh
+${script_dir}/create_remote_repo.sh full_repo
+export build_result=$?
+
+if [ ${build_result} -eq 0 ]; then
+        ${script_dir}/copy_repos.sh
+        export build_result=$?
+fi
+
+echo "Removing locks and destroying VM"
+
+if [[ "$do_not_destroy_vm" != "yes" && "$try_already_running" != "yes" ]] ; then
+  echo "Destroying VM"
+  ${mdbci_dir}/mdbci destroy $name
+fi
+cd $dir
+
+if [ $build_result -ne 0 ] ; then
+        echo "Build FAILED!"
+        exit $build_result
+fi
+

BUILD/mdbci/create_remote_repo.sh

@@ -16,7 +16,12 @@ echo " creating dirs on VM"
 ssh $sshopt "mkdir -p dest ; mkdir -p src; mkdir gpg_keys"
 
 echo "copying stuff to VM"
-scp $scpopt $pre_repo_dir/$target/$box/* $sshuser@$IP:src/
+if [ $1 == "full_repo" ] ; then
+         find  ${repo_path}/maxscale-${major_ver}.*-release/mariadb-maxscale/${platform}/${platform_version}/* -name "*.rpm" -exec scp $scpopt {} $sshuser@$IP:src/ \;
+         find  ${repo_path}/maxscale-${major_ver}.*-release/mariadb-maxscale/${platform}/dists/${platform_version}/* -name "*.deb" -exec scp $scpopt {} $sshuser@$IP:src/ \;
+else
+         scp $scpopt $pre_repo_dir/$target/$box/* $sshuser@$IP:src/
+fi
 
 scp $scpopt -r ${gpg_keys_path}/* $sshuser@$IP:./gpg_keys/
 ssh $sshopt "key=\`ls ~/gpg_keys/*.public -1\` ; gpg --import \$key"

BUILD/mdbci/templates/build.json.template

@@ -3,7 +3,11 @@
   {
         "hostname" : "default",
         "memory_size" : "4096",
-        "box" : "$box"
+        "box" : "$box",
+        "product" : {
+                "name": "docker"
+        }
+
   }
 }
 

include/maxscale/backend.hh

@@ -303,6 +303,16 @@ public:
         return m_state & FATAL_FAILURE;
     }
 
+    /**
+     * Is the backend replaying session command history
+     *
+     * @return If a list of session commands was provided at connect time, the function returns true as long
+     *         as the backend has not completed those session commands.
+     */
+    inline bool is_replaying_history() const
+    {
+        return m_history_size > 0;
+    }
 
     /**
      * @brief Get the object name of this server
@@ -389,7 +399,8 @@ private:
 
     maxbase::StopWatch     m_session_timer;
     maxbase::IntervalTimer m_select_timer;
-    int64_t                m_num_selects = 0;
+    int64_t                m_num_selects {0};
+    int64_t                m_history_size {0};
 };
 
 typedef std::shared_ptr<Backend> SBackend;

maxscale-system-test/CMakeLists.txt

@@ -1001,6 +1001,9 @@ add_test_executable(sr_basics.cpp sr_basics sr_basics LABELS REPL_BACKEND)
 # MXS-2490: Direct execution doesn't work with MaxScale
 add_test_executable(mxs2490_ps_execute_direct.cpp mxs2490_ps_execute_direct replication LABELS REPL_BACKEND readwritesplit)
 
+# MXS-2609: Maxscale crash in RWSplitSession::retry_master_query()
+add_test_executable(mxs2609_history_replay.cpp mxs2609_history_replay mxs2609_history_replay LABELS readwritesplit REPL_BACKEND)
+
 # MXS-2621: Incorrect SQL if lower_case_table_names is used.
 add_test_executable(mxs2621_lower_case_tables.cpp mxs2621_lower_case_tables mxs2621_lower_case_tables LABELS REPL_BACKEND)
 

maxscale-system-test/cnf/maxscale.cnf.template.mxs2609_history_replay

@@ -0,0 +1,27 @@
+[maxscale]
+threads=###threads###
+
+###server###
+
+[MySQL-Monitor]
+type=monitor
+module=mariadbmon
+servers=###server_line###
+user=maxskysql
+password=skysql
+monitor_interval=1000
+
+[RW-Split-Router]
+type=service
+router=readwritesplit
+servers=###server_line###
+user=maxskysql
+password=skysql
+transaction_replay=true
+master_accept_reads=true
+
+[RW-Split-Listener]
+type=listener
+service=RW-Split-Router
+protocol=MySQLClient
+port=4006

maxscale-system-test/mxs2609_history_replay.cpp

@@ -0,0 +1,69 @@
+/**
+ * MXS-2609: Maxscale crash in RWSplitSession::retry_master_query()
+ *
+ * https://jira.mariadb.org/browse/MXS-2609
+ *
+ * This test attempts to reproduce the crash described in MXS-2609 which
+ * occurred during a retrying attempt of a session command that failed on
+ * the master.
+ */
+
+
+#include "testconnections.h"
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    auto block = [&test](int n){
+                     test.repl->block_node(n);
+                     test.maxscales->wait_for_monitor();
+                     test.repl->unblock_node(n);
+                     test.maxscales->wait_for_monitor();
+                 };
+    auto conn = test.maxscales->rwsplit();
+
+    //
+    // Test 1: Master failure mid-reconnect should trigger query replay
+    //
+
+    test.expect(conn.connect(), "First connect should work: %s", conn.error());
+
+    // Queue up session commands so that the history replay takes some time
+    for (int i = 0; i < 10; i++)
+    {
+        conn.query("SET @a = (SLEEP 1)");
+    }
+
+    block(0);
+
+    test.set_timeout(90);
+
+    std::thread([&](){
+                    sleep(5);
+                    block(0);
+                }).detach();
+
+    test.expect(conn.query("SELECT @@last_insert_id"), "Query should work: %s", conn.error());
+
+    test.stop_timeout();
+    conn.disconnect();
+
+    //
+    // Test 2: Exceed history limit and trigger a master reconnection
+    //
+
+    test.maxctrl("alter service RW-Split-Router max_sescmd_history 2");
+    test.expect(conn.connect(), "Second should work: %s", conn.error());
+
+    for (int i = 0; i < 5; i++)
+    {
+        conn.query("SET @a = (SLEEP 1)");
+    }
+
+    block(0);
+
+    test.expect(!conn.query("SELECT @@last_insert_id"), "Query should fail");
+
+    return test.global_result;
+}

server/core/backend.cc

@@ -54,6 +54,7 @@ void Backend::close(close_type type)
         m_closed = true;
         m_closed_at = time(NULL);
         m_session_commands.clear();
+        m_history_size = 0;
 
         if (in_use())
         {
@@ -139,6 +140,12 @@ uint64_t Backend::complete_session_command()
 {
     uint64_t rval = m_session_commands.front()->get_position();
     m_session_commands.pop_front();
+
+    if (m_history_size > 0)
+    {
+        --m_history_size;
+    }
+
     return rval;
 }
 
@@ -192,10 +199,12 @@ bool Backend::connect(MXS_SESSION* session, SessionCommandList* sescmd)
         m_state = IN_USE;
         mxb::atomic::add(&m_backend->connections, 1, mxb::atomic::RELAXED);
         rval = true;
+        m_history_size = 0;
 
-        if (sescmd && sescmd->size())
+        if (sescmd && !sescmd->empty())
         {
             append_session_command(*sescmd);
+            m_history_size = sescmd->size();
 
             if (!execute_session_command())
             {

server/modules/monitor/csmon/csmon.cc

@@ -58,7 +58,7 @@ static std::string do_query(MonitorServer* srv, const char* query)
 // Returns a numeric version similar to mysql_get_server_version
 int get_cs_version(MonitorServer* srv)
 {
-    int rval = 0;
+    int rval = -1;
     std::string prefix = "Columnstore ";
     std::string result = do_query(srv, "SELECT @@version_comment");
     auto pos = result.find(prefix);
@@ -107,16 +107,21 @@ void CsMonitor::update_server_status(MonitorServer* srv)
 
     if (do_query(srv, alive_query) == "1")
     {
-        status |= SERVER_RUNNING;
+        auto version = get_cs_version(srv);
 
-        if (get_cs_version(srv) >= 10200)
+        if (version >= 0)
         {
-            // 1.2 supports the mcsSystemPrimary function
-            status |= do_query(srv, role_query) == "1" ? SERVER_MASTER : SERVER_SLAVE;
-        }
-        else
-        {
-            status |= srv->server == m_primary ? SERVER_MASTER : SERVER_SLAVE;
+            status |= SERVER_RUNNING;
+
+            if (version >= 10200)
+            {
+                // 1.2 supports the mcsSystemPrimary function
+                status |= do_query(srv, role_query) == "1" ? SERVER_MASTER : SERVER_SLAVE;
+            }
+            else
+            {
+                status |= srv->server == m_primary ? SERVER_MASTER : SERVER_SLAVE;
+            }
         }
     }
 

server/modules/routing/readwritesplit/rwsplit_route_stmt.cc

@@ -355,7 +355,7 @@ bool RWSplitSession::route_single_stmt(GWBUF* querybuf)
             else if (target->has_session_commands())
             {
                 // We need to wait until the session commands are executed
-                m_query_queue.emplace_back(gwbuf_clone(querybuf));
+                m_query_queue.emplace_front(gwbuf_clone(querybuf));
                 MXS_INFO("Queuing query until '%s' completes session command", target->name());
             }
             else
@@ -652,7 +652,8 @@ RWBackend* RWSplitSession::get_master_backend()
 
     if (master)
     {
-        if (master->in_use() || (m_config.master_reconnection && master->can_connect()))
+        if (master->in_use()
+            || (m_config.master_reconnection && master->can_connect() && can_recover_servers()))
         {
             if (can_continue_using_master(master))
             {
@@ -667,7 +668,8 @@ RWBackend* RWSplitSession::get_master_backend()
         }
         else
         {
-            MXS_ERROR("Server '%s' is not in use and can't be chosen as the master.",
+            MXS_ERROR("Cannot choose server '%s' as the master because it is not "
+                      "in use and a new connection to it cannot be created.",
                       master->name());
         }
     }

server/modules/routing/readwritesplit/rwsplitsession.cc

@@ -957,17 +957,40 @@ bool RWSplitSession::retry_master_query(RWBackend* backend)
 {
     bool can_continue = false;
 
-    if (backend->has_session_commands())
+    if (backend->is_replaying_history())
     {
-        // Try to route the session command again. If the master is not available, the response will be
-        // returned from one of the slaves.
+        // Master failed while it was replaying the session command history
+        mxb_assert(m_config.master_reconnection);
+        mxb_assert(!m_query_queue.empty());
 
+        retry_query(m_query_queue.front().release());
+        m_query_queue.pop_front();
+        can_continue = true;
+    }
+    else if (backend->has_session_commands())
+    {
+        // We were routing a session command to all servers but the master server from which the response
+        // was expected failed: try to route the session command again. If the master is not available,
+        // the response will be returned from one of the slaves if the configuration allows it.
+
+        mxb_assert(backend->next_session_command()->get_position() == m_recv_sescmd + 1);
+        mxb_assert(m_qc.current_route_info().target() == TARGET_ALL);
         mxb_assert(!m_current_query.get());
         mxb_assert(!m_sescmd_list.empty());
         mxb_assert(m_sescmd_count >= 2);
         MXS_INFO("Retrying session command due to master failure: %s",
                  backend->next_session_command()->to_string().c_str());
 
+        // MXS-2609: Maxscale crash in RWSplitSession::retry_master_query()
+        // To prevent a crash from happening, we make sure the session command list is not empty before
+        // we touch it. This should be converted into a debug assertion once the true root cause of the
+        // problem is found.
+        if (m_sescmd_count < 2 || m_sescmd_list.empty())
+        {
+            MXS_WARNING("Session command list was empty when it should not be");
+            return false;
+        }
+
         // Before routing it, pop the failed session command off the list and decrement the number of
         // executed session commands. This "overwrites" the existing command and prevents history duplication.
         m_sescmd_list.pop_back();
@@ -978,6 +1001,8 @@ bool RWSplitSession::retry_master_query(RWBackend* backend)
     }
     else if (m_current_query.get())
     {
+        // A query was in progress, try to route it again
+        mxb_assert(m_prev_target == backend);
         retry_query(m_current_query.release());
         can_continue = true;
     }