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From David Brower <david.bro...@oracle.com>
Subject Re: can the value of myid > 255?
Date Tue, 20 Dec 2016 17:26:19 GMT
Even if it weren't for the desire to have 1-byte id's for salting into 
session id's, using IP's as the member id will be dubious when you 
anticipate IPv6 addresses.

There might eventually be a need to map 128-bit IP addrs or UUIDs into a 
smaller id space. It's unlikely there will ever be > 255 actual members 
that need to be tracked.  Each member could be tied to a UUID or IP6 
address, and have the mapping to id be done internally from 
configuration that's stored in the ZK tree itself.  This requires an 
add-member that takes the longer identity and stores the mapping.

-dB


On 12/20/2016 9:18 AM, Dan Benediktson wrote:
> I'd strongly suggest you keep the actual value within the range of [0,255]
> so that you can get the benefit of the fix for ZOOKEEPER-2504 whenever the
> patch is accepted.
>
> On Tue, Dec 20, 2016 at 9:11 AM, Michael Han<hanm@cloudera.com>  wrote:
>
>>>> I can not see any limitation on this myid??
>> There is no hard limitation in code that enforce myid is in range of
>> [1..255] - myid is required to be in such range because it's used as server
>> id which is used to generate session id. Each session id should be unique,
>> so this requires the higher 8 bits of the server id (myid) to be unique.
>> See here
>> <https://github.com/apache/zookeeper/blob/master/src/java/main/org/apache/
>> zookeeper/server/SessionTrackerImpl.java#L100>
>> for
>> code reference.
>>
>>>> I want to use the host ip to auto generate myid (ip2long) in bash shell


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