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// strategy_sharded.cpp
#include "stdafx.h"
#include "request.h"
#include "chunk.h"
#include "cursors.h"
#include "../client/connpool.h"
#include "../db/commands.h"
namespace mongo {
class ShardStrategy : public Strategy {
virtual void queryOp( Request& r ){
QueryMessage q( r.d() );
log(3) << "shard query: " << q.ns << " " << q.query << endl;
if ( q.ntoreturn == 1 && strstr(q.ns, ".$cmd") )
throw UserException( "something is wrong, shouldn't see a command here" );
ChunkManager * info = r.getChunkManager();
assert( info );
Query query( q.query );
vector<Chunk*> shards;
info->getChunksForQuery( shards , query.getFilter() );
set<ServerAndQuery> servers;
map<string,int> serverCounts;
for ( vector<Chunk*>::iterator i = shards.begin(); i != shards.end(); i++ ){
servers.insert( ServerAndQuery( (*i)->getShard() , (*i)->getFilter() ) );
int& num = serverCounts[(*i)->getShard()];
num++;
}
ClusteredCursor * cursor = 0;
BSONObj sort = query.getSort();
if ( sort.isEmpty() ){
// 1. no sort, can just hit them in serial
cursor = new SerialServerClusteredCursor( servers , q );
}
else {
int shardKeyOrder = info->getShardKey().canOrder( sort );
if ( shardKeyOrder ){
// 2. sort on shard key, can do in serial intelligently
set<ServerAndQuery> buckets;
for ( vector<Chunk*>::iterator i = shards.begin(); i != shards.end(); i++ ){
Chunk * s = *i;
buckets.insert( ServerAndQuery( s->getShard() , s->getFilter() , s->getMinDotted() ) );
}
cursor = new SerialServerClusteredCursor( buckets , q , shardKeyOrder );
}
else {
// 3. sort on non-sharded key, pull back a portion from each server and iterate slowly
cursor = new ParallelSortClusteredCursor( servers , q , sort );
}
}
assert( cursor );
ShardedClientCursor * cc = new ShardedClientCursor( q , cursor );
if ( ! cc->sendNextBatch( r ) ){
delete( cursor );
return;
}
log(6) << "storing cursor : " << cc->getId() << endl;
cursorCache.store( cc );
}
virtual void getMore( Request& r ){
int ntoreturn = r.d().pullInt();
long long id = r.d().pullInt64();
log(6) << "want cursor : " << id << endl;
ShardedClientCursor * cursor = cursorCache.get( id );
if ( ! cursor ){
log(6) << "\t invalid cursor :(" << endl;
replyToQuery( QueryResult::ResultFlag_CursorNotFound , r.p() , r.m() , 0 , 0 , 0 );
return;
}
if ( cursor->sendNextBatch( r , ntoreturn ) ){
log(6) << "\t cursor finished: " << id << endl;
return;
}
delete( cursor );
cursorCache.remove( id );
}
void _insert( Request& r , DbMessage& d, ChunkManager* manager ){
while ( d.moreJSObjs() ){
BSONObj o = d.nextJsObj();
if ( ! manager->hasShardKey( o ) ){
bool bad = true;
if ( manager->getShardKey().partOfShardKey( "_id" ) ){
BSONObjBuilder b;
b.appendOID( "_id" , 0 , true );
b.appendElements( o );
o = b.obj();
bad = ! manager->hasShardKey( o );
}
if ( bad ){
log() << "tried to insert object without shard key: " << r.getns() << " " << o << endl;
throw UserException( "tried to insert object without shard key" );
}
}
Chunk& c = manager->findChunk( o );
log(4) << " server:" << c.getShard() << " " << o << endl;
insert( c.getShard() , r.getns() , o );
c.splitIfShould( o.objsize() );
}
}
void _update( Request& r , DbMessage& d, ChunkManager* manager ){
int flags = d.pullInt();
BSONObj query = d.nextJsObj();
uassert( "invalid update" , d.moreJSObjs() );
BSONObj toupdate = d.nextJsObj();
BSONObj chunkFinder = query;
bool upsert = flags & Option_Upsert;
bool multi = flags & Option_Multi;
if ( multi )
uassert( "can't mix multi and upsert and sharding" , ! upsert );
if ( upsert && ! manager->hasShardKey( toupdate ) )
throw UserException( "can't upsert something without shard key" );
bool save = false;
if ( ! manager->hasShardKey( query ) ){
if ( multi ){
}
else if ( query.nFields() != 1 || strcmp( query.firstElement().fieldName() , "_id" ) ){
throw UserException( "can't do update with query that doesn't have the shard key" );
}
else {
save = true;
chunkFinder = toupdate;
}
}
if ( ! save ){
if ( toupdate.firstElement().fieldName()[0] == '$' ){
// TODO: check for $set, etc.. on shard key
}
else if ( manager->hasShardKey( toupdate ) && manager->getShardKey().compare( query , toupdate ) ){
throw UserException( "change would move shards!" );
}
}
if ( multi ){
vector<Chunk*> chunks;
manager->getChunksForQuery( chunks , chunkFinder );
set<string> seen;
for ( vector<Chunk*>::iterator i=chunks.begin(); i!=chunks.end(); i++){
Chunk * c = *i;
if ( seen.count( c->getShard() ) )
continue;
doWrite( dbUpdate , r , c->getShard() );
seen.insert( c->getShard() );
}
}
else {
Chunk& c = manager->findChunk( dotted2nested(chunkFinder) );
doWrite( dbUpdate , r , c.getShard() );
c.splitIfShould( d.msg().data->dataLen() );
}
}
void _delete( Request& r , DbMessage& d, ChunkManager* manager ){
int flags = d.pullInt();
bool justOne = flags & 1;
uassert( "bad delete message" , d.moreJSObjs() );
BSONObj pattern = d.nextJsObj();
vector<Chunk*> chunks;
manager->getChunksForQuery( chunks , pattern );
cout << "delete : " << pattern << " \t " << chunks.size() << " justOne: " << justOne << endl;
if ( chunks.size() == 1 ){
doWrite( dbDelete , r , chunks[0]->getShard() );
return;
}
if ( justOne && ! pattern.hasField( "_id" ) )
throw UserException( "can only delete with a non-shard key pattern if can delete as many as we find" );
set<string> seen;
for ( vector<Chunk*>::iterator i=chunks.begin(); i!=chunks.end(); i++){
Chunk * c = *i;
if ( seen.count( c->getShard() ) )
continue;
seen.insert( c->getShard() );
doWrite( dbDelete , r , c->getShard() );
}
}
virtual void writeOp( int op , Request& r ){
const char *ns = r.getns();
log(3) << "write: " << ns << endl;
DbMessage& d = r.d();
ChunkManager * info = r.getChunkManager();
assert( info );
if ( op == dbInsert ){
_insert( r , d , info );
}
else if ( op == dbUpdate ){
_update( r , d , info );
}
else if ( op == dbDelete ){
_delete( r , d , info );
}
else {
log() << "sharding can't do write op: " << op << endl;
throw UserException( "can't do this write op on sharded collection" );
}
}
};
Strategy * SHARDED = new ShardStrategy();
}
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