// DiscoverLoop periodically calls orc.discover() until process termination.
// The Tablet is read from the given agent each time before calling discover().
// Usually this will be launched as a background goroutine.
func (orc *orcClient) DiscoverLoop(agent *ActionAgent) {
if *orcInterval == 0 {
// 0 means never.
return
}
log.Infof("Starting periodic Orchestrator self-registration: API URL = %v, interval = %v", *orcAddr, *orcInterval)
// Randomly vary the interval by +/- 25% to reduce the potential for spikes.
ticker := timer.NewRandTicker(*orcInterval, *orcInterval/4)
// Remember whether we've most recently succeeded or failed.
var lastErr error
for {
// Do the first attempt immediately.
err := orc.Discover(agent.Tablet())
// Only log if we're transitioning between success and failure states.
if (err != nil) != (lastErr != nil) {
if err != nil {
log.Warningf("Orchestrator self-registration attempt failed: %v", err)
} else {
log.Infof("Orchestrator self-registration succeeded.")
}
}
lastErr = err
// Wait for the next tick.
// The only way to stop the loop is to terminate the process.
<-ticker.C
}
}
// NewShardConn creates a new ShardConn. It creates a Balancer using
// serv, cell, keyspace, tabletType and retryDelay. retryCount is the max
// number of retries before a ShardConn returns an error on an operation.
func NewShardConn(ctx context.Context, serv topo.SrvTopoServer, cell, keyspace, shard string, tabletType topodatapb.TabletType, retryDelay time.Duration, retryCount int, connTimeoutTotal, connTimeoutPerConn, connLife time.Duration, tabletConnectTimings *stats.MultiTimings) *ShardConn {
getAddresses := func() (*topodatapb.EndPoints, error) {
endpoints, _, err := serv.GetEndPoints(ctx, cell, keyspace, shard, tabletType)
if err != nil {
return nil, vterrors.NewVitessError(
vtrpcpb.ErrorCode_INTERNAL_ERROR, err,
"endpoints fetch error: %v", err,
)
}
return endpoints, nil
}
blc := NewBalancer(getAddresses, retryDelay)
var ticker *timer.RandTicker
if tabletType != topodatapb.TabletType_MASTER {
ticker = timer.NewRandTicker(connLife, connLife/2)
}
sdc := &ShardConn{
keyspace: keyspace,
shard: shard,
tabletType: tabletType,
retryDelay: retryDelay,
retryCount: retryCount,
connTimeoutTotal: connTimeoutTotal,
connTimeoutPerConn: connTimeoutPerConn,
connLife: connLife,
balancer: blc,
ticker: ticker,
consolidator: sync2.NewConsolidator(),
connectTimings: tabletConnectTimings,
}
if ticker != nil {
go func() {
for range ticker.C {
sdc.closeCurrent()
}
}()
}
return sdc
}