Fix to MXS-29: https://mariadb.atlassian.net/browse/MXS-29

If MAXSCALE_SCHEMA.REPLICATION_HEARTBEAT isn't replicated, a warning is logged.

server/core/modutil.c

@@ -38,6 +38,19 @@ extern int            lm_enabled_logfiles_bitmask;
 extern size_t         log_ses_count[];
 extern __thread log_info_t tls_log_info;
 
+/** These are used when converting MySQL wildcards to regular expressions */
+static SPINLOCK re_lock = SPINLOCK_INIT;
+static bool pattern_init = false;
+static pcre2_code *re_percent = NULL;
+static pcre2_code *re_single = NULL;
+static pcre2_code *re_escape = NULL;
+static const PCRE2_SPTR pattern_percent = (PCRE2_SPTR) "%";
+static const PCRE2_SPTR pattern_single = (PCRE2_SPTR) "([^\\\\]|^)_";
+static const PCRE2_SPTR pattern_escape = (PCRE2_SPTR) "[.]";
+static const char* sub_percent = ".*";
+static const char* sub_single = "$1.";
+static const char* sub_escape = "\\.";
+
 static void modutil_reply_routing_error(
 	DCB*  	 backend_dcb,
 	int   	 error,
@@ -842,3 +855,119 @@ int modutil_count_statements(GWBUF* buffer)
 
     return num;
 }
+
+/**
+ * Initialize the PCRE2 patterns used when converting MySQL wildcards to PCRE syntax.
+ */
+void init_pcre2_patterns()
+{
+    spinlock_acquire(&re_lock);
+    if (!pattern_init)
+    {
+        int err;
+        size_t erroff;
+        PCRE2_UCHAR errbuf[STRERROR_BUFLEN];
+
+        if ((re_percent = pcre2_compile(pattern_percent, PCRE2_ZERO_TERMINATED,
+                                        0, &err, &erroff, NULL)) &&
+            (re_single = pcre2_compile(pattern_single, PCRE2_ZERO_TERMINATED,
+                                       0, &err, &erroff, NULL)) &&
+            (re_escape = pcre2_compile(pattern_escape, PCRE2_ZERO_TERMINATED,
+                                       0, &err, &erroff, NULL)))
+        {
+            pattern_init = true;
+        }
+        else
+        {
+            pcre2_get_error_message(err, errbuf, sizeof(errbuf));
+            skygw_log_write(LE, "Error: Failed to compile PCRE2 pattern: %s",
+                            errbuf);
+        }
+
+        if (!pattern_init)
+        {
+            pcre2_code_free(re_percent);
+            pcre2_code_free(re_single);
+            pcre2_code_free(re_escape);
+            re_percent = NULL;
+            re_single = NULL;
+            re_escape = NULL;
+        }
+    }
+    spinlock_release(&re_lock);
+}
+
+/**
+ * Check if @c string matches @c pattern according to the MySQL wildcard rules.
+ * The wildcard character @c '%%' is replaced with @c '.*' and @c '_' is replaced
+ * with @c '.'. All Regular expression special characters are escaped before
+ * matching is made.
+ * @param pattern Wildcard pattern
+ * @param string String to match
+ * @return MXS_PCRE2_MATCH if the pattern matches, MXS_PCRE2_NOMATCH if it does
+ * not match and MXS_PCRE2_ERROR if an error occurred
+ * @see maxscale_pcre2.h
+ */
+mxs_pcre2_result_t modutil_mysql_wildcard_match(const char* pattern, const char* string)
+{
+    if (!pattern_init)
+    {
+        init_pcre2_patterns();
+    }
+    mxs_pcre2_result_t rval = MXS_PCRE2_ERROR;
+    bool err = false;
+    PCRE2_SIZE matchsize = strlen(string) + 1;
+    PCRE2_SIZE tempsize = matchsize;
+    char* matchstr = (char*) malloc(matchsize);
+    char* tempstr = (char*) malloc(tempsize);
+
+    pcre2_match_data *mdata_percent = pcre2_match_data_create_from_pattern(re_percent, NULL);
+    pcre2_match_data *mdata_single = pcre2_match_data_create_from_pattern(re_single, NULL);
+    pcre2_match_data *mdata_escape = pcre2_match_data_create_from_pattern(re_escape, NULL);
+
+    if (matchstr && tempstr && mdata_percent && mdata_single && mdata_escape)
+    {
+        if (mxs_pcre2_substitute(re_escape, pattern, sub_escape,
+                                 &matchstr, &matchsize) == MXS_PCRE2_ERROR ||
+            mxs_pcre2_substitute(re_single, matchstr, sub_single,
+                                 &tempstr, &tempsize) == MXS_PCRE2_ERROR ||
+            mxs_pcre2_substitute(re_percent, tempstr, sub_percent,
+                                 &matchstr, &matchsize) == MXS_PCRE2_ERROR)
+        {
+            err = true;
+        }
+
+        if (!err)
+        {
+            int errcode;
+            rval = mxs_pcre2_simple_match(matchstr, string, PCRE2_CASELESS, &errcode);
+            if (rval == MXS_PCRE2_ERROR)
+            {
+                if(errcode != 0)
+                {
+                    PCRE2_UCHAR errbuf[STRERROR_BUFLEN];
+                    pcre2_get_error_message(errcode, errbuf, sizeof(errbuf));
+                    skygw_log_write(LE, "Error: Failed to match pattern: %s",
+                                    errbuf);
+                }
+                err = true;
+            }
+        }
+    }
+    else
+    {
+        err = true;
+    }
+
+    if (err)
+    {
+        skygw_log_write(LE, "Error: Fatal error when matching wildcard patterns.");
+    }
+
+    pcre2_match_data_free(mdata_percent);
+    pcre2_match_data_free(mdata_single);
+    pcre2_match_data_free(mdata_escape);
+    free(matchstr);
+    free(tempstr);
+    return rval;
+}

server/include/modutil.h

@@ -34,6 +34,7 @@
 #include <buffer.h>
 #include <dcb.h>
 #include <string.h>
+#include <maxscale_pcre2.h>
 
 #define PTR_IS_RESULTSET(b) (b[0] == 0x01 && b[1] == 0x0 && b[2] == 0x0 && b[3] == 0x01)
 #define PTR_IS_EOF(b) (b[0] == 0x05 && b[1] == 0x0 && b[2] == 0x0 && b[4] == 0xfe)
@@ -68,4 +69,5 @@ GWBUF *modutil_create_mysql_err_msg(
 	const char	*msg);
 
 int modutil_count_signal_packets(GWBUF*,int,int,int*);
+mxs_pcre2_result_t modutil_mysql_wildcard_match(const char* pattern, const char* string);
 #endif

server/modules/monitor/mysql_mon.c

@@ -51,8 +51,9 @@
  * @endverbatim
  */
 
-
 #include <mysqlmon.h>
+#include <pcre2.h>
+#include <modutil.h>
 
 /** Defined in log_manager.cc */
 extern int            lm_enabled_logfiles_bitmask;
@@ -81,7 +82,10 @@ static void set_master_heartbeat(MYSQL_MONITOR *, MONITOR_SERVERS *);
 static void set_slave_heartbeat(MONITOR *, MONITOR_SERVERS *);
 static int add_slave_to_master(long *, int, long);
 bool isMySQLEvent(monitor_event_t event);
+void check_maxscale_schema_replication(MONITOR *monitor);
 static bool report_version_err = true;
+static const char* hb_table_name = "maxscale_schema.replication_heartbeat";
+
 static MONITOR_OBJECT MyObject = { 
 	startMonitor, 
 	stopMonitor, 
@@ -219,6 +223,7 @@ startMonitor(void *arg, void* opt)
     {
 	memset(handle->events,true,sizeof(handle->events));
     }
+
     handle->tid = (THREAD)thread_start(monitorMain, monitor);
     return handle;
 }
@@ -734,6 +739,7 @@ int num_servers=0;
 MONITOR_SERVERS *root_master = NULL;
 size_t nrounds = 0;
 int log_no_master = 1;
+bool heartbeat_checked = false;
 
 spinlock_acquire(&mon->lock);
 handle = (MYSQL_MONITOR *)mon->handle;
@@ -762,6 +768,13 @@ detect_stale_master = handle->detectStaleMaster;
 		}
 		/** Wait base interval */
 		thread_millisleep(MON_BASE_INTERVAL_MS);
+
+		if (handle->replicationHeartbeat && !heartbeat_checked)
+		{
+			check_maxscale_schema_replication(mon);
+			heartbeat_checked = true;
+		}
+
 		/** 
 		 * Calculate how far away the monitor interval is from its full 
 		 * cycle and if monitor interval time further than the base 
@@ -1465,3 +1478,223 @@ bool isMySQLEvent(monitor_event_t event)
     }
     return false;
 }
+
+/**
+ * Check if replicate_ignore_table is defined and if maxscale_schema.replication_hearbeat
+ * table is in the list.
+ * @param database Server to check
+ * @return False if the table is not replicated or an error occurred when querying
+ * the server
+ */
+bool check_replicate_ignore_table(MONITOR_SERVERS* database)
+{
+    MYSQL_RES *result;
+    bool rval = true;
+
+    if (mysql_query(database->con,
+                    "show variables like 'replicate_ignore_table'") == 0 &&
+        (result = mysql_store_result(database->con)) &&
+        mysql_num_fields(result) > 1)
+    {
+        MYSQL_ROW row;
+
+        while ((row = mysql_fetch_row(result)))
+        {
+            if (strlen(row[1]) > 0 &&
+                strcasestr(row[1], hb_table_name))
+            {
+                skygw_log_write(LE, "Warning: 'replicate_ignore_table' is "
+                                "defined on server '%s' and '%s' was found in it. ",
+                                database->server->unique_name, hb_table_name);
+                rval = false;
+            }
+        }
+
+        mysql_free_result(result);
+    }
+    else
+    {
+        skygw_log_write(LE, "Error: Failed to query server %s for "
+                        "'replicate_ignore_table': %s",
+                        database->server->unique_name,
+                        mysql_error(database->con));
+        rval = false;
+    }
+    return rval;
+}
+
+/**
+ * Check if replicate_do_table is defined and if maxscale_schema.replication_hearbeat
+ * table is not in the list.
+ * @param database Server to check
+ * @return False if the table is not replicated or an error occurred when querying
+ * the server
+ */
+bool check_replicate_do_table(MONITOR_SERVERS* database)
+{
+    MYSQL_RES *result;
+    bool rval = true;
+
+    if (mysql_query(database->con,
+                    "show variables like 'replicate_do_table'") == 0 &&
+        (result = mysql_store_result(database->con)) &&
+        mysql_num_fields(result) > 1)
+    {
+        MYSQL_ROW row;
+
+        while ((row = mysql_fetch_row(result)))
+        {
+            if (strlen(row[1]) > 0 &&
+                strcasestr(row[1], hb_table_name) == NULL)
+            {
+                skygw_log_write(LE, "Warning: 'replicate_do_table' is "
+                                "defined on server '%s' and '%s' was not found in it. ",
+                                database->server->unique_name, hb_table_name);
+                rval = false;
+            }
+        }
+        mysql_free_result(result);
+    }
+    else
+    {
+        skygw_log_write(LE, "Error: Failed to query server %s for "
+                        "'replicate_do_table': %s",
+                        database->server->unique_name,
+                        mysql_error(database->con));
+        rval = false;
+    }
+    return rval;
+}
+
+/**
+ * Check if replicate_wild_do_table is defined and if it doesn't match
+ * maxscale_schema.replication_heartbeat.
+ * @param database Database server
+ * @return False if the table is not replicated or an error occurred when trying to
+ * query the server.
+ */
+bool check_replicate_wild_do_table(MONITOR_SERVERS* database)
+{
+    MYSQL_RES *result;
+    bool rval = true;
+
+    if (mysql_query(database->con,
+                    "show variables like 'replicate_wild_do_table'") == 0 &&
+        (result = mysql_store_result(database->con)) &&
+        mysql_num_fields(result) > 1)
+    {
+        MYSQL_ROW row;
+
+        while ((row = mysql_fetch_row(result)))
+        {
+            if (strlen(row[1]) > 0)
+            {
+                mxs_pcre2_result_t rc = modutil_mysql_wildcard_match(row[1], hb_table_name);
+                if (rc == MXS_PCRE2_NOMATCH)
+                {
+                    skygw_log_write(LE, "Warning: 'replicate_wild_do_table' is "
+                                    "defined on server '%s' and '%s' does not match it. ",
+                                    database->server->unique_name,
+                                    hb_table_name);
+                    rval = false;
+                }
+            }
+        }
+        mysql_free_result(result);
+    }
+    else
+    {
+        skygw_log_write(LE, "Error: Failed to query server %s for "
+                        "'replicate_wild_do_table': %s",
+                        database->server->unique_name,
+                        mysql_error(database->con));
+        rval = false;
+    }
+    return rval;
+}
+
+
+/**
+ * Check if replicate_wild_ignore_table is defined and if it matches
+ * maxscale_schema.replication_heartbeat.
+ * @param database Database server
+ * @return False if the table is not replicated or an error occurred when trying to
+ * query the server.
+ */
+bool check_replicate_wild_ignore_table(MONITOR_SERVERS* database)
+{
+    MYSQL_RES *result;
+    bool rval = true;
+
+    if (mysql_query(database->con,
+                    "show variables like 'replicate_wild_ignore_table'") == 0 &&
+        (result = mysql_store_result(database->con)) &&
+        mysql_num_fields(result) > 1)
+    {
+        MYSQL_ROW row;
+
+        while ((row = mysql_fetch_row(result)))
+        {
+            if (strlen(row[1]) > 0)
+            {
+                mxs_pcre2_result_t rc = modutil_mysql_wildcard_match(row[1], hb_table_name);
+                if (rc == MXS_PCRE2_MATCH)
+                {
+                    skygw_log_write(LE, "Warning: 'replicate_wild_ignore_table' is "
+                                    "defined on server '%s' and '%s' matches it. ",
+                                    database->server->unique_name,
+                                    hb_table_name);
+                    rval = false;
+                }
+            }
+        }
+        mysql_free_result(result);
+    }
+    else
+    {
+        skygw_log_write(LE, "Error: Failed to query server %s for "
+                        "'replicate_wild_do_table': %s",
+                        database->server->unique_name,
+                        mysql_error(database->con));
+        rval = false;
+    }
+    return rval;
+}
+
+/**
+ * Check if the maxscale_schema.replication_heartbeat table is replicated on all
+ * servers and log a warning if problems were found.
+ * @param monitor Monitor structure
+ */
+void check_maxscale_schema_replication(MONITOR *monitor)
+{
+    MONITOR_SERVERS* database = monitor->databases;
+    bool err = false;
+
+    while (database)
+    {
+        connect_result_t rval = mon_connect_to_db(monitor, database);
+        if (rval == MONITOR_CONN_OK)
+        {
+            if (!check_replicate_ignore_table(database) ||
+                !check_replicate_do_table(database) ||
+                !check_replicate_wild_do_table(database) ||
+                !check_replicate_wild_ignore_table(database))
+            {
+                err = true;
+            }
+        }
+        else
+        {
+            mon_log_connect_error(database, rval);
+        }
+        database = database->next;
+    }
+
+    if (err)
+    {
+        skygw_log_write(LE, "Warning: Problems were encountered when "
+                        "checking if '%s' is replicated. Make sure that the table is "
+                        "replicated to all slaves.", hb_table_name);
+    }
+}