Merge branch '2.3' into develop

server/core/config.cc

@@ -2984,7 +2984,7 @@ void config_set_global_defaults()
     gateway.peer_password[0] = '\0';
     gateway.log_target = MXB_LOG_TARGET_DEFAULT;
 
-    gateway.qc_cache_properties.max_size = get_total_memory() * 0.4;
+    gateway.qc_cache_properties.max_size = get_total_memory() * 0.15;
 
     if (gateway.qc_cache_properties.max_size == 0)
     {

server/core/dcb.cc

@@ -513,6 +513,7 @@ int dcb_read(DCB* dcb,
              GWBUF** head,
              int maxbytes)
 {
+    mxb_assert(dcb->owner == RoutingWorker::get_current());
     int nsingleread = 0;
     int nreadtotal = 0;
 
@@ -853,6 +854,7 @@ static int dcb_log_errors_SSL(DCB* dcb, int ret)
  */
 int dcb_write(DCB* dcb, GWBUF* queue)
 {
+    mxb_assert(dcb->owner == RoutingWorker::get_current());
     dcb->writeqlen += gwbuf_length(queue);
     // The following guarantees that queue is not NULL
     if (!dcb_write_parameter_check(dcb, queue))
@@ -2825,6 +2827,7 @@ public:
         RoutingWorker& rworker = static_cast<RoutingWorker&>(worker);
         if (dcb_is_still_valid(m_dcb, rworker.id()) && m_dcb->m_uid == m_uid)
         {
+            mxb_assert(m_dcb->owner == RoutingWorker::get_current());
             m_dcb->fakeq = m_buffer;
             dcb_handler(m_dcb, m_ev);
         }
@@ -2845,6 +2848,7 @@ static void poll_add_event_to_dcb(DCB* dcb, GWBUF* buf, uint32_t ev)
 {
     if (dcb == this_thread.current_dcb)
     {
+        mxb_assert(dcb->owner == RoutingWorker::get_current());
         // If the fake event is added to the current DCB, we arrange for
         // it to be handled immediately in dcb_handler() when the handling
         // of the current events are done...

server/core/query_classifier.cc

@@ -177,10 +177,15 @@ public:
         mxb_assert(peek(canonical_stmt) == nullptr);
         mxb_assert(this_unit.classifier);
 
+        // 0xffffff is the maximum packet size, 4 is for packet header and 1 is for command byte. These are
+        // MariaDB/MySQL protocol specific values that are also defined in <maxscale/protocol/mysql.h> but
+        // should not be exposed to the core.
+        constexpr int64_t max_entry_size = 0xffffff - 5;
+
         int64_t cache_max_size = this_unit.cache_max_size() / config_get_global_options()->n_threads;
         int64_t size = canonical_stmt.size();
 
-        if (size <= cache_max_size)
+        if (size < max_entry_size && size <= cache_max_size)
         {
             int64_t required_space = (m_stats.size + size) - cache_max_size;
 

server/modules/monitor/csmon/csmon.cc

@@ -58,17 +58,22 @@ 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)
 {
-    // GCC 4.8 appears to have a broken std::regex_constants::ECMAScript that doesn't support brackets
-    std::regex re("Columnstore \\([0-9]*\\)[.]\\([0-9]*\\)[.]\\([0-9]*\\)-[0-9]*",
-                  std::regex_constants::basic);
-    std::string result = do_query(srv, "SELECT @@version_comment");
-    std::smatch match;
     int rval = 0;
+    std::string prefix = "Columnstore ";
+    std::string result = do_query(srv, "SELECT @@version_comment");
+    auto pos = result.find(prefix);
 
-    if (std::regex_match(result, match, re) && match.size() == 4)
+    if (pos != std::string::npos)
     {
-        rval = atoi(match[1].str().c_str()) * 10000 + atoi(match[2].str().c_str()) * 100
-            + atoi(match[3].str().c_str());
+        std::istringstream os(result.substr(pos + prefix.length()));
+        int major = 0, minor = 0, patch = 0;
+        char dot;
+        os >> major;
+        os >> dot;
+        os >> minor;
+        os >> dot;
+        os >> patch;
+        rval = major * 10000 + minor * 100 + patch;
     }
 
     return rval;

server/modules/protocol/MySQL/mariadb_client.cc

@@ -32,6 +32,8 @@ LocalClient::LocalClient(MYSQL_session* session, MySQLProtocol* proto, int fd)
     , m_self_destruct(false)
 {
     MXB_POLL_DATA::handler = LocalClient::poll_handler;
+    m_protocol.owner_dcb = nullptr;
+    m_protocol.stored_query = nullptr;
 }
 
 LocalClient::~LocalClient()

server/modules/protocol/MySQL/rwbackend.cc

@@ -304,6 +304,17 @@ void RWBackend::process_packets(GWBUF* result)
         auto end = std::next(it, len);
         uint8_t cmd = *it;
 
+        // Ignore the tail end of a large packet large packet. Only resultsets can generate packets this large
+        // and we don't care what the contents are and thus it is safe to ignore it.
+        bool skip_next = m_skip_next;
+        m_skip_next = len == GW_MYSQL_MAX_PACKET_LEN;
+
+        if (skip_next)
+        {
+            it = end;
+            continue;
+        }
+
         switch (m_reply_state)
         {
         case REPLY_STATE_START:

server/modules/routing/avrorouter/avro_client.cc

@@ -33,6 +33,7 @@
 #include <maxscale/alloc.h>
 #include <maxscale/buffer.hh>
 #include <maxscale/utils.hh>
+#include <maxscale/routingworker.hh>
 
 std::pair<std::string, std::string> get_avrofile_and_gtid(std::string file);
 
@@ -238,22 +239,14 @@ bool file_in_dir(const char* dir, const char* file)
 }
 
 /**
- * @brief The client callback for sending data
- *
- * @param dcb Client DCB
- * @param reason Why the callback was called
- * @param userdata Data provided when the callback was added
- * @return Always 0
+ * Queue the client callback for execution
  */
-int avro_client_callback(DCB* dcb, DCB_REASON reason, void* userdata)
+void AvroSession::queue_client_callback()
 {
-    if (reason == DCB_REASON_DRAINED)
-    {
-        AvroSession* client = static_cast<AvroSession*>(userdata);
-        client->client_callback();
-    }
-
-    return 0;
+    auto worker = mxs::RoutingWorker::get(mxs::RoutingWorker::MAIN);
+    worker->execute([this]() {
+                        client_callback();
+                    }, mxs::RoutingWorker::EXECUTE_QUEUED);
 }
 
 /**
@@ -337,11 +330,7 @@ void AvroSession::process_command(GWBUF* queue)
 
             if (file_in_dir(router->avrodir.c_str(), avro_binfile.c_str()))
             {
-                /* set callback routine for data sending */
-                dcb_add_callback(dcb, DCB_REASON_DRAINED, avro_client_callback, this);
-
-                /* Add fake event that will call the avro_client_callback() routine */
-                poll_fake_write_event(dcb);
+                queue_client_callback();
             }
             else
             {
@@ -733,7 +722,7 @@ void AvroSession::client_callback()
 
     if (next_file || read_more)
     {
-        poll_fake_write_event(dcb);
+        queue_client_callback();
     }
 }
 

server/modules/routing/avrorouter/avrorouter.hh

@@ -173,11 +173,6 @@ public:
      */
     int routeQuery(GWBUF* buffer);
 
-    /**
-     * Handler for the EPOLLOUT event
-     */
-    void client_callback();
-
 private:
     AvroSession(Avro* instance, MXS_SESSION* session);
 
@@ -190,6 +185,8 @@ private:
     bool seek_to_gtid();
     bool stream_data();
     void rotate_avro_file(std::string fullname);
+    void client_callback();
+    void queue_client_callback();
 };
 
 void read_table_info(uint8_t* ptr,