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Add EventCacheCount as member of BinlogSyncerConfig to limit streamer's event channel size #830

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Merged
merged 5 commits into from
Oct 12, 2023
Merged

Add EventCacheCount as member of BinlogSyncerConfig to limit streamer's event channel size #830

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f866148
lower memory usage by reducing event chan size in streamer
zing22845 Oct 9, 2023
9987311
make streamer's event chan size configurable
zing22845 Oct 9, 2023
e85bf72
update cfg name StreamerChanSize to EventCacheSize
zing22845 Oct 11, 2023
7455b04
Merge branch 'master' into master
zing22845 Oct 11, 2023
ef58cab
EventCacheSize is renamed to EventCacheCount, to make the variable na…
zing22845 Oct 12, 2023
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10 changes: 9 additions & 1 deletion replication/binlogstreamer.go
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Original file line number Diff line number Diff line change
Expand Up @@ -85,9 +85,17 @@ func (s *BinlogStreamer) closeWithError(err error) {
}

func NewBinlogStreamer() *BinlogStreamer {
return NewBinlogStreamerWithChanSize(10240)
}

func NewBinlogStreamerWithChanSize(chanSize int) *BinlogStreamer {
s := new(BinlogStreamer)

s.ch = make(chan *BinlogEvent, 10240)
if chanSize <= 0 {
chanSize = 10240
}

s.ch = make(chan *BinlogEvent, chanSize)
s.ech = make(chan error, 4)

return s
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7 changes: 6 additions & 1 deletion replication/binlogsyncer.go
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Expand Up @@ -122,6 +122,8 @@ type BinlogSyncerConfig struct {
RowsEventDecodeFunc func(*RowsEvent, []byte) error

DiscardGTIDSet bool

EventCacheSize int
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The name "XXXSize" makes me think it's using the unit of memory, (EventCacheSize = 1024 means the cache will not exceed 1KB), maybe "EventCacheCount" is a better name.

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Agreed! I'll work on the fixes.

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Directly limiting memory usage requires dynamically calculating the memory occupancy of the Event Cache during the streaming process, which might lead to a decrease in overall efficiency.
In scenarios where the network conditions are not too poor, even setting the EventCacheCount to a single digit won't have much worse performance compared to 10240, while at the same time, the memory of the Event Cache will be limited to the size of a few Events, which is enough to achieve a balance between efficiency and resource occupancy.

}

// BinlogSyncer syncs binlog event from server.
Expand Down Expand Up @@ -166,6 +168,9 @@ func NewBinlogSyncer(cfg BinlogSyncerConfig) *BinlogSyncer {
dialer := &net.Dialer{}
cfg.Dialer = dialer.DialContext
}
if cfg.EventCacheSize == 0 {
cfg.EventCacheSize = 10240
}

// Clear the Password to avoid outputing it in log.
pass := cfg.Password
Expand Down Expand Up @@ -393,7 +398,7 @@ func (b *BinlogSyncer) prepare() error {
func (b *BinlogSyncer) startDumpStream() *BinlogStreamer {
b.running = true

s := NewBinlogStreamer()
s := NewBinlogStreamerWithChanSize(b.cfg.EventCacheSize)

b.wg.Add(1)
go b.onStream(s)
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