diff --git a/resultdb/sink/artifact_channel.go b/resultdb/sink/artifact_channel.go
index <HASH>..<HASH> 100644
--- a/resultdb/sink/artifact_channel.go
+++ b/resultdb/sink/artifact_channel.go
@@ -61,7 +61,7 @@ func newArtifactChannel(ctx context.Context, cfg *ServerConfig) *artifactChannel
 			//
 			// The dispatcher uploads only the first item in each Batch.
 			BatchSize:    1,
-			MaxLeases:    4,
+			MaxLeases:    16,
 			FullBehavior: &buffer.BlockNewItems{MaxItems: 4000},
 		},
 	}
[resultdb] increase max_lease of artifact upload channel from 4 to <I>

R=<EMAIL>,<EMAIL>
CC=<EMAIL>

Bug: <I>
Change-Id: I<I>fc4c<I>e3e<I>fe<I>a<I>fa1b<I>b<I>
Reviewed-on: <URL>