Multiple records updating throws optimistic locking in mongo #618
Description
I have a daily scheduled grails job which updates the properties of users with changes from last date. It goes like this
try {
// Daily job for updating user orders
DateTime yesterday = new DateTime().withZone(DateTimeZone.getDefault()).withTimeAtStartOfDay().minusDays(1)
userService.updateStatsForAllUsers(yesterday)
}
catch (Exception e) {
println e.getCause()
}
UserService
void updateStatsForAllUsers(DateTime date) {
List<User> customers = User.list()
List<Order> orders = null
customers.each { customer ->
orders = customer.orders?.findAll{it.status.equals("DELIVERED")}?.sort{it?.dateCreated}
if (orders?.size() > 0) {
customer.firstOrderDate = orders?.first()?.dateCreated
customer.lastOrderDate = orders?.last()?.dateCreated
customer.totalOrders = orders.size()
customer.save(flush: true)
}
}
}
i am not able to understand that the loop is updating different objects , then why does it throws optimistic lock exception, we have a user base of around 50k, and this job always throws a OptimisticLockingException on user save., how can we handle this, is there any way for such batch update using grails mongo.