There are a few issues related to topic names. First, we have some topic
specific metrics and jmx bean name has certain restrictions (e.g., no space
allowed and maybe others). Second, in 0.8, we have a file that stores high
watermarks. It's a simple text file and expects 1 line per topic/partition.
If topic name has '\r' or '\n', it could mess up the format of the file. A
simple solution is to restrict topic names to ASCII alpha-numeric
characters (plus _ and -) in 0.8. We can try to relax it in the future.
Anybody has concerns with this?

Thanks,

Jun

I have no objection, though it may be no harder just to escape the
newlines. I agree it is probably better to start strict if we aren't sure.

-Jay

On Tue, Sep 25, 2012 at 9:16 AM, Jun Rao <[EMAIL PROTECTED]> wrote:

> There are a few issues related to topic names. First, we have some topic
> specific metrics and jmx bean name has certain restrictions (e.g., no space
> allowed and maybe others). Second, in 0.8, we have a file that stores high
> watermarks. It's a simple text file and expects 1 line per topic/partition.
> If topic name has '\r' or '\n', it could mess up the format of the file. A
> simple solution is to restrict topic names to ASCII alpha-numeric
> characters (plus _ and -) in 0.8. We can try to relax it in the future.
> Anybody has concerns with this?
>
> Thanks,
>
> Jun
>

+1 to restrict topic names to ASCII alpha-numeric characters (plus _ and -) in 0.8

I think a compelling case has to be made ( with some real world use cases ) to change this rule if adopted.
On Sep 25, 2012, at 12:16 PM, Jun Rao <[EMAIL PROTECTED]> wrote:

> There are a few issues related to topic names. First, we have some topic
> specific metrics and jmx bean name has certain restrictions (e.g., no space
> allowed and maybe others). Second, in 0.8, we have a file that stores high
> watermarks. It's a simple text file and expects 1 line per topic/partition.
> If topic name has '\r' or '\n', it could mess up the format of the file. A
> simple solution is to restrict topic names to ASCII alpha-numeric
> characters (plus _ and -) in 0.8. We can try to relax it in the future.
> Anybody has concerns with this?
>
> Thanks,
>
> Jun

We are patching 0.8 to allow only ASCII alpha-numeric characters, plus _
and - in topic names. Plus the maxTopicNameLength is being hardcoded to
255 chars. The patch is at KAFKA-495.

Thanks,
Swapnil

On 9/25/12 3:15 PM, "Joe Stein" <[EMAIL PROTECTED]> wrote:

>+1 to restrict topic names to ASCII alpha-numeric characters (plus _ and
>-) in 0.8
>
>I think a compelling case has to be made ( with some real world use cases
>) to change this rule if adopted.
>
>
>On Sep 25, 2012, at 12:16 PM, Jun Rao <[EMAIL PROTECTED]> wrote:
>
>> There are a few issues related to topic names. First, we have some topic
>> specific metrics and jmx bean name has certain restrictions (e.g., no
>>space
>> allowed and maybe others). Second, in 0.8, we have a file that stores
>>high
>> watermarks. It's a simple text file and expects 1 line per
>>topic/partition.
>> If topic name has '\r' or '\n', it could mess up the format of the
>>file. A
>> simple solution is to restrict topic names to ASCII alpha-numeric
>> characters (plus _ and -) in 0.8. We can try to relax it in the future.
>> Anybody has concerns with this?
>>
>> Thanks,
>>
>> Jun