use pipe from pool cause "bytes.Buffer: truncation out of range"

[wangxingge]

I have a pool connect to a redis instance. I create this pool as following: _pool, err := pool.New("tcp", address, 100)

And there are 300 goroutine use this pool to send command. most of them using pool as following,(we call it: eg1) _pool.Cmd(cmd, args)

And 50 goroutine user this pipe from this pool, like following(we canll it: eg2) c, err :=_pool.Get() c.PipeAppend(cmd, args) c.PipeAppend(cmd, args) c.PipeAppend(cmd, args) c.PipeResp()

Problem is: eg1 will throw a panic error: bytes.Buffer: truncation out of range

CallStack like following.

goroutine 83 [running]: bytes.(_Buffer).Truncate(0xc8205e3500, 0x0) /usr/local/go/src/bytes/buffer.go:69 +0xbf bytes.(_Buffer).WriteTo(0xc8205e3500, 0x7fe8513a6868, 0xc82029c050, 0x33, 0x0, 0x0) /usr/local/go/src/bytes/buffer.go:222 +0x1af github.com/mediocregopher/radix.v2/redis.(_Client).writeRequest(0xc8212a6180, 0xc8500a2ea8, 0x1, 0x1, 0x0, 0x0) /home/stanford/golang/src/github.com/mediocregopher/radix.v2/redis/client.go:172 +0x5e3 github.com/mediocregopher/radix.v2/redis.(_Client).Cmd(0xc8212a6180, 0x9116b8, 0x4, 0xc853140320, 0x1, 0x1, 0x7c6780) /home/stanford/golang/src/github.com/mediocregopher/radix.v2/redis/client.go:85 +0x12b github.com/mediocregopher/radix.v2/pool.(*Pool).Cmd(0xc8212c24e0, 0x9116b8, 0x4, 0xc853140320, 0x1, 0x1, 0x0) /home/stanford/golang/src/github.com/mediocregopher/radix.v2/pool/pool.go:95 +0x104

BTW, I'm not using the lasted version of radix pool.

I'll try last version later.

[wangxingge]

But it's worked when I create a new connection to use pipe. You know it's low efficiency.

[mediocregopher]

Hey there! I'm afraid I'm having a bit of trouble understanding what you're doing. My two suggestions just based on your sample code are to make sure you're calling Put on the Pool once you're done with your Pipe* commands, and to make sure you call PipeResp the same number of times you call PipeAppend. Although neither of those should really cause a panic.

Can you explain what you mean by using a pipe to create a new connection?

On Fri, May 27, 2016 at 12:13 AM wangxingge notifications@github.com wrote:

But it's worked, when I use pipe then to create a new connection. You know it's low efficiency.

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[wangxingge]

Sorry for reply so late.

I'v review your method of "PipeResp", its send all pending command to redis, by invoke "ReadResp" in loop. So I append many time and just call PipeResp once, then i found if i used the connection from pool, panic will be thrown.

So I create a new connection, and this new connection not get from pool. Create code following: con := redis.DialTimeout("tcp", _workAbleAdd, 10*time.Second)

con.PipeAppend con.PipeAppend con.PipeAppend con.PipeResp

BTW, I'm very appreciate your quick response/

[mediocregopher]

It's true you don't have to do a PipeResp all 3 times, and all the responses will have been read from the connection. But the Client is buffering those answers internally, so if you're going to use that connection again later (which you will, since you're using a pool) you don't want those staying buffered because they'll cause problems later. You should at least call PipeClear to get rid of the buffered answers you don't want.

On Sat, May 28, 2016 at 11:41 PM wangxingge notifications@github.com wrote:

Sorry for reply so late.

I'v review your method of "PipeResp", its send all pending command to redis, and invoke "ReadResp". So I append many time and just call PipeResp once.

Create a new connection means. con := redis.DialTimeout("tcp", _workAbleAdd, 10*time.Second)

con.PipeAppend con.PipeAppend con.PipeAppend con.PipeResp

BTW, I'm very appreciate your quick response/

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[wangxingge]

Thank you, I got it, it review "PipeClear" function, I'll update to lasted version of radix driver.

Thanks a lot.

[mediocregopher]

No problem, let me know if you have any other questions :)

On Sun, May 29, 2016 at 7:09 PM wangxingge notifications@github.com wrote:

Closed #27 https://github.com/mediocregopher/radix.v2/issues/27.

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[wangxingge]

Works now. :+1: