Mycat源码解读--错误之【find no Route】
Mycat之find no Route:SELECT * FROM `db1`.`t_gaojs` LIMIT 0
错误原因竟然是：DruidSelectParser类中的tryRoute方法
1、后台报错，前台竟然可以查询出数据
2017-03-01 20:37:59,312 [WARN ][$_NIOREACTOR-3-RW] ServerConnection [id=1, schema=TESTDB, host=127.0.0.1, user=root,txIsolation=3, autocommit=true, schema=TESTDB]SELECT * FROM `db1`.`t_gaojs` LIMIT 0 err:java.sql.SQLNonTransientException: find no Route:SELECT * FROM `db1`.`t_gaojs` LIMIT 0 java.sql.SQLNonTransientException: find no Route:SELECT * FROM `db1`.`t_gaojs` LIMIT 0
at io.mycat.route.parser.druid.impl.DruidSelectParser.tryRoute(DruidSelectParser.java:437)
错误原因竟然是：DruidSelectParser类中的tryRoute方法
private void tryRoute(SchemaConfig schema, RouteResultset rrs,
LayerCachePool cachePool) throws SQLNonTransientException {
if(rrs.isFinishedRoute())
{
return;//避免重复路由
}
//无表的select语句直接路由带任一节点
if((ctx.getTables() == null || ctx.getTables().size() == 0)
&&(ctx.getTableAliasMap()==null||ctx.getTableAliasMap().isEmpty())) {
rrs = RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), ctx.getSql());
rrs.setFinishedRoute(true);
return;
}
//RouterUtil.tryRouteForTables(schema, ctx, rrs, true, cachePool);
SortedSet<RouteResultsetNode> nodeSet = new TreeSet<RouteResultsetNode>();
boolean isAllGlobalTable = RouterUtil.isAllGlobalTable(ctx, schema);
for (RouteCalculateUnit unit : ctx.getRouteCalculateUnits()) {
RouteResultset rrsTmp = RouterUtil.tryRouteForTables(schema, ctx, unit, rrs, true, cachePool);
if (rrsTmp != null&&rrsTmp.getNodes()!=null) {
for (RouteResultsetNode node : rrsTmp.getNodes()) {
nodeSet.add(node);
}
}
if(isAllGlobalTable) {//都是全局表时只计算一遍路由
break;
}
}
if(nodeSet.size() == 0) {
Collection<String> stringCollection= ctx.getTableAliasMap().values() ;
for (String table : stringCollection)
{
if(table!=null&&table.toLowerCase().contains("information_schema."))
{
rrs = RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), ctx.getSql());
rrs.setFinishedRoute(true);
return;
}
}
String msg = " find no Route:" + ctx.getSql();
LOGGER.warn(msg);
throw new SQLNonTransientException(msg);
}
RouteResultsetNode[] nodes = new RouteResultsetNode[nodeSet.size()];
int i = 0;
for (Iterator<RouteResultsetNode> iterator = nodeSet.iterator(); iterator.hasNext();) {
nodes[i] = (RouteResultsetNode) iterator.next();
i++;
}
rrs.setNodes(nodes);
rrs.setFinishedRoute(true);
}