Comment 4 for bug 1260283

in general, the process of updating a provider is
1. reload provider (previous wsrep_provider_options value is gone. use built-in value in galera code)
2. set wsrep_provider_options
3. set wsrep_clutser_address (connect to cluster and then start replication)

Most parameters in wsrep_provder_options should be set *before* connecting to cluster, like gcache.*, repl.* etc. However some parameters could only be set *after* connecting to cluster. AFAIK, these parameters include
a. protonet.*
b. socket.*
c. gmcast.*
d. evs.*
e. pc.*

So if you are gonna to set pc.bootstrap=1, you can only do it after you set wsrep_clutser_address .