Handle ETCD event cleared exception during blocking lock #250
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Currently if a lock is held by someone and you try to perform a blocking acquire, its possible for ETCD to return a 401 (etcd.EtcdEventIndexCleared) when more than 1000 events have occurred since the key was modified. This gets caught here https://github.com/jplana/python-etcd/blob/master/src/etcd/lock.py#L130 and another watch call is made with the same arguments which will again fail leaving it in a
while Trueloop of repeated calls that fail.ETCD docs ( https://coreos.com/etcd/docs/latest/v2/api.html#waiting-for-a-change. ) describe how you recover from this situation by performing a get to obtain the current state and starting a watch from etcd-index + 1 .