Thank you. And for completeness sake, here is the full function I'm using,
just in case something else is wrong. Rather than calling the capabilities
APIs on every hit, I cache the value in a global variable and check every 30
seconds.
*from google.appengine.api import capabilities*
*
*
*# Store in a global variable so it's cached between requests.*
*capabilities_check_time = None;*
*datastore_writes_enabled = True;*
*
*
*def in_read_only_mode():*
* """We return True if we're in read-only mode or going to read-only one
in *
* 30 seconds or less. But we check the APIs every once in a while to
avoid*
* the extra load that causes."""*
*
*
* global capabilities_check_time, datastore_writes_enabled*
*
*
* buffer_in_seconds = 30 # consider us in read-only mode this much time
before we actually get there*
* check_period_in_seconds = 30 # time between checking the capabilities
APIs*
* now = datetime.datetime.now()*
*
*
* if capabilities_check_time and capabilities_check_time > now:*
* # we don't need to check the APIs we have enough info cached*
* return not(datastore_writes_enabled)*
* else:*
* # we need to check the capabilities *
* # todo: check we check memcache as well?*
* datastore_writes = capabilities.CapabilitySet('datastore_v3',
capabilities=['write'])*
* datastore_writes_enabled = \*
* datastore_writes.will_remain_enabled_for(buffer_in_seconds +
check_period_in_seconds)*
* capabilities_check_time = now +
datetime.timedelta(seconds=check_period_in_seconds)*
* return not(datastore_writes_enabled)*
* *
*
*
On Sat, Jun 12, 2010 at 2:28 PM, App Engine Team <
appengine.nore...@gmail.com> wrote:
> Hmm, okay we're looking into what's going on.
>
> On Jun 12, 2:23 pm, Waleed Abdulla <wal...@ninua.com> wrote:
> > Thanks for the info.
> >
> > I updated my app to detect the read-only mode per Jason's
> presentation[1].
> > However, now that it's in read-only mode, my app is not detecting it. So
> the
> > preparations I coded are not working and things are failing badly rather
> > than gracefully :(
> >
> > This is the code I'm using:
> >
> > datastore_writes = capabilities.CapabilitySet('datastore_v3',
> > capabilities=['write'])
> > datastore_writes_enabled = \
> > datastore_writes.will_remain_enabled_for(60)
> >
> > I'm expecting to have datastore_writes_enabled be False when in read-only
> > mode, but it's not !!
> >
> > Waleed
> > [1]
> http://www.slideshare.net/jasonacooper/strategies-for-maintaining-app...
> >
> > On Sat, Jun 12, 2010 at 2:12 PM, App Engine Team <
> >
> > appengine.nore...@gmail.com> wrote:
> > > Hey Waleed
> >
> > > The first half of the maintenance period was actually done without
> > > going read-only. We have just enabled read-only now.
> >
> > > On Jun 12, 1:49 pm, Waleed Abdulla <wal...@ninua.com> wrote:
> > > > It was supposed to start at 1pm. I wonder if it's already in progress
> or
> > > not
> > > > started yet!
> >
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