func (c *ClusterClient) process(cmd Cmder) {
var ask bool
slot := hashtag.Slot(cmd.clusterKey())
addr := c.slotMasterAddr(slot)
client, err := c.getClient(addr)
if err != nil {
cmd.setErr(err)
return
}
for attempt := 0; attempt <= c.opt.getMaxRedirects(); attempt++ {
if attempt > 0 {
cmd.reset()
}
if ask {
pipe := client.Pipeline()
pipe.Process(NewCmd("ASKING"))
pipe.Process(cmd)
_, _ = pipe.Exec()
pipe.Close()
ask = false
} else {
client.Process(cmd)
}
// If there is no (real) error, we are done!
err := cmd.Err()
if err == nil {
return
}
// On network errors try random node.
if shouldRetry(err) {
client, err = c.randomClient()
if err != nil {
return
}
continue
}
var moved bool
var addr string
moved, ask, addr = isMovedError(err)
if moved || ask {
if moved && c.slotMasterAddr(slot) != addr {
c.lazyReloadSlots()
}
client, err = c.getClient(addr)
if err != nil {
return
}
continue
}
break
}
}
// Watch creates new transaction and marks the keys to be watched
// for conditional execution of a transaction.
func (c *ClusterClient) Watch(keys ...string) (*Multi, error) {
addr := c.slotMasterAddr(hashtag.Slot(keys[0]))
client, err := c.getClient(addr)
if err != nil {
return nil, err
}
return client.Watch(keys...)
}
func (pipe *ClusterPipeline) Exec() (cmds []Cmder, retErr error) {
if pipe.closed {
return nil, pool.ErrClosed
}
if len(pipe.cmds) == 0 {
return []Cmder{}, nil
}
cmds = pipe.cmds
pipe.cmds = make([]Cmder, 0, 10)
cmdsMap := make(map[string][]Cmder)
for _, cmd := range cmds {
slot := hashtag.Slot(cmd.clusterKey())
addr := pipe.cluster.slotMasterAddr(slot)
cmdsMap[addr] = append(cmdsMap[addr], cmd)
}
for attempt := 0; attempt <= pipe.cluster.opt.getMaxRedirects(); attempt++ {
failedCmds := make(map[string][]Cmder)
for addr, cmds := range cmdsMap {
client, err := pipe.cluster.getClient(addr)
if err != nil {
setCmdsErr(cmds, err)
retErr = err
continue
}
cn, err := client.conn()
if err != nil {
setCmdsErr(cmds, err)
retErr = err
continue
}
failedCmds, err = pipe.execClusterCmds(cn, cmds, failedCmds)
if err != nil {
retErr = err
}
client.putConn(cn, err, false)
}
cmdsMap = failedCmds
}
return cmds, retErr
}