Websocket data transmission, canvas line drawing problem

the front and rear ends transmit data through websocket. When drawing line segments in canvas, I first need to clear the canvas, and then draw dots and line segments. If this is the case, the data transfer is relatively fast and flicker will occur. Which god knows other ways? thank you.

Apr.02,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e46c2d-44bf3.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e46c2d-44bf3.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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