CLUSTER RESET: Flush dataset if node is a slave.

For non-empty masters, CLUSTER RESET is denied, and the user requires to
start to reset a node by explicitly clearing it with FLUSHALL.
However CLUSTER RESET when executed with slaves don't have this
restrictions since data is just a replica of the master, and with
read-only slaves it is also not possible to remove the data set. However
the node was turned from slave to master after a reset, without touching
the old slave data. This is 99.99% of times not appropriate and forces
full resets to follow this path to work with both slave and master
nodes:

    FLUSHALL
    CLUSTER RESET HARD
    FLUSHALL

Since we need the first flushall for masters, and the second for slaves.

This commit changes the behavior so that CLUSTER RESET removes the data set
of a slave node during a reset, in the moment it gets turned into a master,
so the new pattern is simply:

    FLUSHALL (that may fail for slaves)
    CLUSTER RESET
This commit is contained in:
antirez 2014-07-22 15:29:57 +02:00
parent 10088d5087
commit 89af463124

View File

@ -481,7 +481,8 @@ void clusterInit(void) {
* 3) If the node is a slave, it turns into a master.
* 5) Only for hard reset: a new Node ID is generated.
* 6) Only for hard reset: currentEpoch and configEpoch are set to 0.
* 7) The new configuration is saved and the cluster state updated. */
* 7) The new configuration is saved and the cluster state updated.
* 8) If the node was a slave, the whole data set is flushed away. */
void clusterReset(int hard) {
dictIterator *di;
dictEntry *de;
@ -491,6 +492,7 @@ void clusterReset(int hard) {
if (nodeIsSlave(myself)) {
clusterSetNodeAsMaster(myself);
replicationUnsetMaster();
emptyDb(NULL);
}
/* Close slots, reset manual failover state. */