Error in private$trans$read(sz)

[randyzwitch]

When calling some thrift methods, I do get a valid response. However for some, I just get Error in private$trans$read(sz) : as my error, with no real clue about the problem.

Posting here for now, will try and debug some and come back with either a reproducible example or more information

[randyzwitch]

Pretty sure the issue is here, though trying to dig in further.

https://github.com/systemincloud/thriftr/blob/c82252919ee16d4ba9a8f1b594b81cf619d5b33b/R/protocol_binary.R#L316

[marekjagielski]

Is there no stacktrase or anything more? At the end transport is implemented here: https://github.com/systemincloud/thriftr/blob/c82252919ee16d4ba9a8f1b594b81cf619d5b33b/R/transport_socket.R Probably not the best error handling

read = function(sz) {
      ret <- readBin(self$sock, raw(), sz)
      if (length(ret) == 0) {
        stop()
      }
      ret
}

But maybe you are ending in this stop().

[marekjagielski]

Please add some message to it (worth contribution). If it is here, next question is why you get empty ret.

[randyzwitch]

I'm using the actual R debugger, not doing statements. I'll try to dig into this further, it's pretty hard to follow this generated code TBH :laughing:

[randyzwitch]

I can confirm the problem is here:

read = function(sz) {
      ret <- readBin(self$sock, raw(), sz)
      if (length(ret) == 0) {
        stop()
      }
      ret
}

I commented out the stop() statement, and it caused the function to never return. So that's not a proper fix.

My hypothesis is that the error is ocurring because of empty struct fields. In thriftpy, here's the result of the call that is erroring out in thriftr:

In [7]: client.get_memory(conn, "cpu")                                          
Out[7]: [TNodeMemoryInfo(host_name='', page_size=512, max_num_pages=25692761, num_pages_allocated=0, is_allocation_capped=False, node_memory_data=[])]

You can see that in two places, host_name and node_memory_data there are empty values.

[marekjagielski]

The hangs are because socketConnection is 'blocking' function.

I would check here: https://github.com/systemincloud/thriftr/blob/9fe1d7224cf9aedfe5d7fe4baf9b2f90463887c4/R/protocol_binary.R#L243 if the size 'sz' is 0. If yes, probably we shouldn't do 'inbuf$read(sz)' at all.

[marekjagielski]

The same for LIST: https://github.com/systemincloud/thriftr/blob/9fe1d7224cf9aedfe5d7fe4baf9b2f90463887c4/R/protocol_binary.R#L264

[marekjagielski]

@randyzwitch can you check the newest master version with your example? I added handling for empty strings, lists and maps.

[randyzwitch]

Work is a little crazy right now, but hope to check this out in the next couple of days

[randyzwitch]

These updates look promising! I tried the equivalent R version of client.get_memory(conn, "cpu") that worked in Python and it returned a result in R. I also tried another method and it also returned.

I need to spend a little more time with this, as R6 in general is a bit hard for me to parse, but it does look like you caught the issue.

[marekjagielski]

If you find any more problems with this, please reopen this bug.

[randyzwitch]

Will do, thanks for all your work to fix this

On Thu, Mar 28, 2019 at 4:06 PM Marek Jagielski notifications@github.com wrote:

If you find any more problems with this, please reopen this bug.

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