Well, on windows Vista and below (haven't checked on 7), System.currentTimeMillis only has around 10ms granularity. That is for any 10ms period, you get the same value. I develop on Windows and I'd get sporadic integration test failures due to this.
On Thu, Sep 1, 2011 at 8:31 PM, Jeremiah Jordan < jeremiah.jor...@morningstar.com> wrote: > Are you running on windows? If the default timestamp is just using > time.time()*1e6 you will get the same timestamp twice if the code is close > together. time.time() on windows is only millisecond resolution. I don't > use pycassa, but in the Thrift api wrapper I created for our python code I > implemented the following function for getting timestamps: > > def GetTimeInMicroSec(): > """ > Returns the current time in microseconds, returned value always > increases with each call. > > :return: Current time in microseconds > """ > newTime = long(time.time()*1e6) > try: > if GetTimeInMicroSec.lastTime >= newTime: > newTime = GetTimeInMicroSec.lastTime + 1 > except AttributeError: > pass > GetTimeInMicroSec.lastTime = newTime > return newTime > > > On 08/29/2011 04:56 PM, Peter Schuller wrote: > >> If the client sleeps for a few ms at each loop, the success rate >>> increases. At 15 ms, the script always succeeds so far. Interestingly, >>> the problem seems to be sensitive to alphabetical order. Updating the >>> value from 'aaa' to 'bbb' never has problem. No pause needed. >>> >> Is it possible the version of pycassa you're using does not guarantee >> that successive queries use non-identical and monotonically increasing >> timestamps? I'm just speculating, but if that is the case and two >> requests are sent with the same timestamp (due to resolution being >> lower than the time it takes between calls), the tie breaking would be >> the column value which jives with the fact that you're saying it seems >> to depend on the value. >> >> (I haven't checked current nor past versions of pycassa to determine >> if this is plausible. Just speculating.) >> >> -- --------------------------------------------- Paul Loy p...@keteracel.com http://uk.linkedin.com/in/paulloy
