In the GAE/J documentation for "Gracefully Degrading During Scheduled Maintenance" it states
"Note: Because App Engine for Java sessions are backed by memcache and the datastore, sessions are effectively disabled during read-only periods. You must take this into account when designing your application." My code for detecting datastore down-times failed during last Saturday's scheduled down-time. It attempts to detect a down-time by writing to the mem cache using a StrictErrorHandler, and responding to any MemcacheServiceException raised to disable parts of my web site which write to the datastore, but I got severe errors before this got detected: com.google.apphosting.api.ApiProxy$CapabilityDisabledException: The API call datastore_v3.Put() is temporarily unavailable. This could be my fault in many ways (perhaps the mem cache stayed up). In particular, I suspect that my app's use of sessions is at fault. The relevant fragment of my "appengine-web.xml" config is: <appengine-web-app xmlns="http://appengine.google.com/ns/1.0";> ... <sessions-enabled>true</sessions-enabled> ... </appengine-web-app> This may be a silly question, but in what ways can one anticipate, detect and handle the disabling of sessions during a datastore down- time period? -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
