Concurrent upsert causes deadlock. Is it normal? #12366
Description
Hello everyone!
I conduct small perftest on my local deplyment of ignite3, with 2 threads making 50% upsert and 50% get operations on random index:
public static void main(String[] args) throws Exception
{
String[] addresses = {
"localhost:10800",
"localhost:10801",
"localhost:10802"
};
try (IgniteClient client = IgniteClient.builder()
.addresses(addresses)
.connectTimeout(30000)
.build()) {
Runnable runnable = new Runnable() {
@Override
public void run() {
Random randomOp = new Random();
Random randomIndex = new Random();
Table perftest =client.tables().table("perftest");
long start = System.currentTimeMillis();
int N = 70000;
for (int i=0;i<N; i++) {
// 50% upsert, 50% get
if (randomOp.nextInt(10) <5 )
perftest.recordView().upsert(null, Tuple.create().set("id", randomIndex.nextLong(1000)).set("val", RandGeneratedStr(1000)));
else
perftest.recordView().get(null,Tuple.create().set("id", randomIndex.nextLong(1000)));
}
long end =System.currentTimeMillis();
System.out.println("Rate: "+N*1.0*1000/(end-start));
}
};
Thread t1 = new Thread(runnable);
Thread t2 = new Thread(runnable);
t1.start();
t2.start();
t1.join();
t2.join();
}
}
And when i run two concurrent threads, i get one of them failed with:
IGN-TX-4 TraceId:205ebf31-614f-4ab1-bb3c-c017ab57ec09 Failed to acquire a lock due to a possible deadlock
I see, that each upsert requires X lock on key (smth like this LockKey [ctx=42_part_11, key=RowId [partitionId=11, uuid=00000199-7235-8748-3904-4e30efc61428]]) and get requires S lock on key. All upserts by one key should be serialized? getiing X-lock one by one. So what is the reason of deadlock and how can i prevent it in concurrent workloads?