This is mostly from memory. But the last 12 ? (4096 decimal) bits are a counter for the number of id's generated in a particular millisecond for that server. You could use the high 4 bits in that range for your data type flags and the low 8 for the counter.
Aaron On 1/03/2011, at 4:41 AM, Ertio Lew <ertio...@gmail.com> wrote: > Hi Ryan, > > I am considering snowflake as an option for my usage with Cassandra > for a distributed application. > As I came to know snowflake uses 64 bits IDs. I am looking for a > solution that could help me generate 64 bits Ids > but in those 64 bits I would like at least 4 free bits so that I could > manipulate with those free bits to distinguish the two rows for a same > entity(split by kind of data) in same column family. > > If I could keep the snowflake's Id size to around 60 bits, that would > be great for my use case. Is it possible to manipulate the bits safely > to around 60 bits? Perhaps the microsecond precision is not required > to that much depth for my use case. > > Any kind of suggestions would be appreciated. > > Best Regards > Ertio Lew > > > > > > > > On Fri, Feb 4, 2011 at 1:09 AM, Ryan King <r...@twitter.com> wrote: >> You could also consider snowflake: >> >> http://github.com/twitter/snowflake >> >> which gives you ids that roughly sort by time (but aren't sequential). >> >> -ryan >> >> On Thu, Feb 3, 2011 at 11:13 AM, Matthew E. Kennedy >> <matt.kenn...@spadac.com> wrote: >>> Unless you need your user identifiers to be sequential for some reason, I >>> would save yourself the headache of this kind of complexity and just use >>> UUIDs if you have to generate an identifier. >>> >>> On Feb 3, 2011, at 2:03 PM, Aklin_81 wrote: >>> >>>> Hi all, >>>> To generate new keys/ UserIds for new users on my application, I am >>>> thinking of using a simple synchronized counter that can keep track of >>>> the no. of users registered on my application and when a new user >>>> signs up, he can be allotted the next available id. >>>> >>>> Since Cassandra is eventually consistent, Is this advisable to >>>> implement with Cassandra, but then I could also use stronger >>>> consistency level like quorum or all for this purpose. >>>> >>>> >>>> Please let me know your thoughts and suggesttions.. >>>> >>>> Regards >>>> Asil >>> >>> >> >> >> >> -- >> @rk >>
