Do not emit error as it closes the internal DB's connection stream and the Pool needs to keep it open to reuse the the connection

lib/api/sql/copy-controller.js

@@ -123,7 +123,7 @@ function handleCopyFrom (logger) {
                     metrics.end(null, err);
                     pgstream.emit('error', err);
                 })
-                .on('close', () => pgstream.emit('error', new Error('Connection closed by client')))
+                .on('close', () => pgstream.emit('client-close', new Error('Connection closed by client')))
                 .pipe(throttle)
                 .pipe(decompress)
                 .on('data', data => {

lib/services/stream-copy.js

@@ -56,7 +56,7 @@ module.exports = class StreamCopy {
                     pgstream.on('warning', (msg) => this.logger.warn(msg));
                 } else if (action === ACTION_FROM) {
                     pgstream.on('finish', () => done());
-                    pgstream.on('error', err => client.connection.sendCopyFail(err.message));
+                    pgstream.on('client-close', err => client.connection.sendCopyFail(err.message));
                 }
 
                 pgstream.on('error', err => done(err));