Unable to resolve "Command processing" (#YG4)

[matiasgarcia]

I’m stuck on Stage #YG4

I believe I am facing some race conditions when sending the commands to the replicas, but I am having a hard time to understand where’s the problem.

Here are my logs:

tester::#HD5] [handshake] Received "FULLRESYNC b8b6e5ee4a5e6b1628df86d459349fd4acbbbe37 0"
[tester::#HD5] [handshake] Reading RDB file...
[your_program] << $88
[your_program] REDIS0011�       redis-ver7.2.0�
[your_program] redis-bits�@�ctime��eused-mem°�aof-base���n;���Z�
[your_program] push
[tester::#HD5] [handshake] replica-3: Received bytes: "$88\r\nREDIS0011\xfa\tredis-ver\x057.2.0\xfa\nredis-bits\xc0@\xfa\x05ctime\xc2m\b\xbce\xfa\bused-mem°\xc4\x10\x00\xfa\baof-base\xc0\x00\xff\xf0n;\xfe\xc0\xffZ\xa2"
[tester::#HD5] [handshake] Received RDB file
[tester::#HD5] [test] client: $ redis-cli SET foo 123
[tester::#HD5] [test] client: Sent bytes: "*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\n123\r\n"
[your_program] >> "*3 $3 SET $3 foo $3 123"
[your_program] <<[fwd][127.0.0.1:45902] "*3 $3 SET $3 foo $3 123"
[your_program] <<[fwd][127.0.0.1:45908] "*3 $3 SET $3 foo $3 123"
[your_program] <<[fwd][127.0.0.1:45912] "*3 $3 SET $3 foo $3 123"
[your_program] << "+OK "
[tester::#HD5] [test] client: Received bytes: "+OK\r\n"
[tester::#HD5] [test] client: Received RESP simple string: "OK"
[tester::#HD5] [test] Received "OK"
[tester::#HD5] [test] client: > SET bar 456
[tester::#HD5] [test] client: Sent bytes: "*3\r\n$3\r\nSET\r\n$3\r\nbar\r\n$3\r\n456\r\n"
[your_program] >> "*3 $3 SET $3 bar $3 456"
[your_program] <<[fwd][127.0.0.1:45902] "*3 $3 SET $3 bar $3 456"
[your_program] <<[fwd][127.0.0.1:45908] "*3 $3 SET $3 bar $3 456"
[your_program] <<[fwd][127.0.0.1:45912] "*3 $3 SET $3 bar $3 456"
[your_program] << "+OK "
[tester::#HD5] [test] client: Received bytes: "+OK\r\n"
[tester::#HD5] [test] client: Received RESP simple string: "OK"
[tester::#HD5] [test] Received "OK"
[tester::#HD5] [test] client: > SET baz 789
[tester::#HD5] [test] client: Sent bytes: "*3\r\n$3\r\nSET\r\n$3\r\nbaz\r\n$3\r\n789\r\n"
[your_program] >> "*3 $3 SET $3 baz $3 789"
[your_program] <<[fwd][127.0.0.1:45902] "*3 $3 SET $3 baz $3 789"
[your_program] <<[fwd][127.0.0.1:45908] "*3 $3 SET $3 baz $3 789"
[your_program] <<[fwd][127.0.0.1:45912] "*3 $3 SET $3 baz $3 789"
[your_program] << "+OK "
[tester::#HD5] [test] client: Received bytes: "+OK\r\n"
[tester::#HD5] [test] client: Received RESP simple string: "OK"
[tester::#HD5] [test] Received "OK"
[tester::#HD5] [test] Testing Replica: 1/3
[tester::#HD5] [test] replica-1: Expecting "SET foo 123" to be propagated
[tester::#HD5] Received: "ET\r\n$3\r\nfoo\r\n$3\r\n123*3\r\n$3\r\nSE"
[tester::#HD5]                                        ^ error
[tester::#HD5] Error: Expected \r\n after 3 bytes of data in bulk string
[tester::#HD5] Test failed
[tester::#HD5] Terminating program
[tester::#HD5] Program terminated successfully

And here’s a snippet of my code:

support RESP array in replication

[andy1li]

Hi @matiasgarcia, I tried running your code against the previous stages, but it’s no longer passing #zn8 Single-replica propagation.

Suggestions:

1. Use our CLI to test against previous stages by running:

codecrafters test --previous

2. Focus on fixing the early stages first, as later stages depend on them.

[matiasgarcia]

Hi! I fixed the bug so I could make progress, but stuck on the replconf ack. Not really understand whats going on, it seems a race condition keeps triggering from time to time. Any hints?

[andy1li]

Sorry the delayed response! I added a log here:

function receiveCommands(connection: net.Socket) {
  connection.on("data", (stream) => {
    const commands = collectCommands(stream);
    commands.forEach((c) => {
+     console.debug(`⛳`, c.toString("ascii"));
      processCommand(c, connection);
    });
  });
}

Looks like the RDB file sent by the master wasn’t properly handled:

[andy1li]

Closing this thread due to inactivity. If you still need assistance, feel free to reopen or start a new discussion!