MXS-3613: Add support for metadata skip

The MARIADB_CLIENT_CACHE_METADATA flag is now advertised by MaxScale and understood by the result parsing code. Added the RCAP_TYPE_NO_METADATA_CACHE routing flag to allow the feature to be disabled for modules that don't support the caching of metadata. Currently cache, masking and smartrouter modules do not support it as they use different code for processing the result metadata.
mariadb-corporation · Jun 16, 2021 · 305b17d · 305b17d
1 parent 08b46a8
commit 305b17d
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Showing 7 changed files with 38 additions and 10 deletions.
diff --git a/include/maxscale/protocol/mariadb/mysql.hh b/include/maxscale/protocol/mariadb/mysql.hh
@@ -298,14 +298,19 @@ enum gw_mysql_capabilities_t
  * Since we only use these in the non-shifted form, the definitions declared here
  * are right shifted by 32 bytes and can be directly copied into the extra capabilities.
  */
-#define MXS_MARIA_CAP_PROGRESS             (1 << 0)
-#define MXS_MARIA_CAP_COM_MULTI            (1 << 1)
-#define MXS_MARIA_CAP_STMT_BULK_OPERATIONS (1 << 2)
+#define MXS_MARIA_CAP_PROGRESS             (1UL << 0)
+#define MXS_MARIA_CAP_COM_MULTI            (1UL << 1)
+#define MXS_MARIA_CAP_STMT_BULK_OPERATIONS (1UL << 2)
+#define MXS_MARIA_CAP_EXTENDED_TYPES       (1UL << 3)   // Added in 10.5
+#define MXS_MARIA_CAP_CACHE_METADATA       (1UL << 4)   // Added in 10.6
 
 // Default extended flags that MaxScale supports
-constexpr const uint32_t MXS_EXTRA_CAPABILITIES_SERVER = MXS_MARIA_CAP_STMT_BULK_OPERATIONS;
+constexpr const uint32_t MXS_EXTRA_CAPABILITIES_SERVER =
+    MXS_MARIA_CAP_STMT_BULK_OPERATIONS
+    | MXS_MARIA_CAP_CACHE_METADATA;
+
 // Same as above, for uint64.
-constexpr const uint64_t MXS_EXTRA_CAPS_SERVER64 = (1ul << 34u);
+constexpr const uint64_t MXS_EXTRA_CAPS_SERVER64 = ((uint64_t)MXS_EXTRA_CAPABILITIES_SERVER << 32);
 
 enum mxs_mysql_cmd_t
 {

diff --git a/include/maxscale/routing.hh b/include/maxscale/routing.hh
@@ -137,6 +137,13 @@ enum mxs_routing_capability_t
      * Binary: 0b0000000100000000
      */
     RCAP_TYPE_SESCMD_HISTORY = (1 << 8),
+
+    /**
+     * Disables the metadata caching extension that was added to MariaDB in 10.6.
+     *
+     * Binary: 0b0000001000000000
+     */
+    RCAP_TYPE_NO_METADATA_CACHE = (1 << 9),
 };
 
 #define RCAP_TYPE_NONE 0

diff --git a/server/modules/filter/cache/cachefilter.cc b/server/modules/filter/cache/cachefilter.cc
@@ -31,7 +31,8 @@ namespace
 {
 
 static char VERSION_STRING[] = "V1.0.0";
-constexpr uint64_t CAPABILITIES = RCAP_TYPE_TRANSACTION_TRACKING | RCAP_TYPE_REQUEST_TRACKING;
+constexpr uint64_t CAPABILITIES = RCAP_TYPE_TRANSACTION_TRACKING | RCAP_TYPE_REQUEST_TRACKING
+    | RCAP_TYPE_NO_METADATA_CACHE;
 
 /**
  * Implement "call command cache show ..."

diff --git a/server/modules/filter/masking/maskingfilter.cc b/server/modules/filter/masking/maskingfilter.cc
@@ -86,7 +86,7 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
         MXS_FILTER_VERSION,
         "A masking filter that is capable of masking/obfuscating returned column values.",
         "V1.0.0",
-        RCAP_TYPE_STMT_INPUT | RCAP_TYPE_STMT_OUTPUT,
+        RCAP_TYPE_STMT_INPUT | RCAP_TYPE_STMT_OUTPUT | RCAP_TYPE_NO_METADATA_CACHE,
         &mxs::FilterApi<MaskingFilter>::s_api,
         NULL,   /* Process init. */
         NULL,   /* Process finish. */
@@ -169,7 +169,7 @@ json_t* MaskingFilter::diagnostics() const
 // static
 uint64_t MaskingFilter::getCapabilities() const
 {
-    return RCAP_TYPE_STMT_INPUT | RCAP_TYPE_STMT_OUTPUT;
+    return RCAP_TYPE_STMT_INPUT | RCAP_TYPE_STMT_OUTPUT | RCAP_TYPE_NO_METADATA_CACHE;
 }
 
 std::shared_ptr<MaskingRules> MaskingFilter::rules() const

diff --git a/server/modules/protocol/MariaDB/mariadb_backend.cc b/server/modules/protocol/MariaDB/mariadb_backend.cc
@@ -2231,6 +2231,7 @@ void MariaDBBackendConnection::process_reply_start(Iter it, Iter end)
 void MariaDBBackendConnection::process_result_start(Iter it, Iter end)
 {
     uint8_t cmd = *it;
+    MYSQL_session* data = static_cast<MYSQL_session*>(m_session->protocol_data());
 
     switch (cmd)
     {
@@ -2279,7 +2280,15 @@ void MariaDBBackendConnection::process_result_start(Iter it, Iter end)
         // Start of a result set
         m_num_coldefs = get_encoded_int(it);
         m_reply.add_field_count(m_num_coldefs);
-        set_reply_state(ReplyState::RSET_COLDEF);
+
+        if ((data->extra_capabilitites() & MXS_MARIA_CAP_CACHE_METADATA) && *it == 0)
+        {
+            set_reply_state(ReplyState::RSET_COLDEF_EOF);
+        }
+        else
+        {
+            set_reply_state(ReplyState::RSET_COLDEF);
+        }
         break;
     }
 }

diff --git a/server/modules/protocol/MariaDB/mariadb_client.cc b/server/modules/protocol/MariaDB/mariadb_client.cc
@@ -388,6 +388,12 @@ bool MariaDBClientConnection::send_server_handshake()
         // extended capabilities.
         caps &= ~GW_MYSQL_CAPABILITIES_CLIENT_MYSQL;
         caps |= MXS_EXTRA_CAPS_SERVER64;
+
+        if (service->capabilities() & RCAP_TYPE_NO_METADATA_CACHE)
+        {
+            caps &= ~(MXS_MARIA_CAP_CACHE_METADATA << 32);
+            mxb_assert((caps & MXS_EXTRA_CAPS_SERVER64) == (MXS_MARIA_CAP_STMT_BULK_OPERATIONS << 32));
+        }
     }
 
     if (require_ssl())

diff --git a/server/modules/routing/smartrouter/smartrouter.cc b/server/modules/routing/smartrouter/smartrouter.cc
@@ -56,7 +56,7 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
         MXS_ROUTER_VERSION,
         "Provides routing for the Smart Query feature",
         "V1.0.0",
-        RCAP_TYPE_TRANSACTION_TRACKING | RCAP_TYPE_STMT_INPUT | RCAP_TYPE_STMT_OUTPUT,
+        RCAP_TYPE_TRANSACTION_TRACKING | RCAP_TYPE_STMT_INPUT | RCAP_TYPE_STMT_OUTPUT | RCAP_TYPE_NO_METADATA_CACHE,
         &mxs::RouterApi<SmartRouter>::s_api,
         nullptr,    /* Process init. */
         nullptr,    /* Process finish. */