MySQL Bugs: #79840: SSH Tunnel queries hang

Bug #79840	SSH Tunnel queries hang
Submitted:	5 Jan 2016 5:18	Modified:	23 Jan 2017 19:03
Reporter:	Jay Paroline	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Workbench: SQL Editor	Severity:	S2 (Serious)
Version:	6.3.6	OS:	Windows
Assigned to:		CPU Architecture:	Any

Description:
Possibly a duplicate of https://bugs.mysql.com/bug.php?id=74557 - but that is marked closed and this issue still happens on the latest version.

When running large queries over an SSH tunnel, mysql workbench hangs indefinitely. Over a standard TCP/IP connection, works fine.

How to repeat:
Set up SSH tunnel, select 1k rows on a large table

Hello Jay Paroline,

Thank you for the report.
Observed this with WB 6.3.6 on Win7.

Thanks,
Umesh

// How to repeat

CREATE DATABASE IF NOT EXISTS test;
use test;
CREATE TABLE tt (mycol varchar(1024) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1;

insert into tt values (repeat('A',1024)),(repeat('A',1024)),(repeat('A',1024)),(repeat('A',1024));
insert into tt(mycol) select repeat('A',1024)  from tt k1, tt k2, tt k3, tt k4,tt k5,tt k6, tt k7, tt k8, tt k9,tt k0,tt ka, tt kb, tt kc, tt kd limit 100000;

CREATE TABLE ttt (mycol varchar(1024) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8 AS SELECT * from tt limit 90000;

-- Try using connection methods Standard TCP/IP over SSH and Standard TCP/IP
-- Observed that former method hangs when querying SELECT * FROM test.tt with limit 1K rows..

-- MySQL server 5.7.10 running over OL7, WB on Win7

Bug #73343 marked as duplicate of this

Bug #79931 marked as duplicate of this

Bug #77443 marked as duplicate of this

I've encountered what I believe to be the same bug, but it wasn't happening when running against MySQL server 5.5.47 (linux). When I upgraded to server 5.6.28 (same box and setup), I started encountering the issue. The query works fine if executed from a client local to the server. Smaller queries also work fine local or remote - it's just large queries remotely across a SSH tunnel that seem to be causing issues. Workbench version in both cases was 6.3.6.

This is a big issue with me. I don't have a very large table or an extreme amount of data, due the program regularly freezes. It keeps getting reported as a duplicate of older bugs. Some of the reports go back over a year. What is being done to address this???

I've repeated this on 6.3.6 with windows->ubuntu on a relatively small table returning fewer than 400 rows (see http://bugs.mysql.com/bug.php?id=81073)

http://bugs.mysql.com/bug.php?id=81073 marked as duplicate of this one.

This problem is definitely around and i see many with this problem.
I have two servers, one with MySQL 5.5.43 and one with 5.6.29.
I work with different mysql workbench  versions and there is no problem working with MySQL 5.5.43. When working with 5.6.29 and SELECTING with LIMIT over 500 workbench hangs...

This issues still happens on 3.6.7 build 1199 (x64).

Enables WAN compression help a little bit, but if the compressed data gets too big it will hang regardless.

There seems to be a hard limit as to the amount of bytes that the SSH tunnels seems to be able to support at any one time.

Same problem, however I have noticed that the problem occurs when more than x amount of data is returned which is why for some people it's 400 rows and others 1000. A simple 2 col select will be successful up to 5000 rows, whereas select * from may only be a few hundred. Wish this long-standing bug would be sorted already

I have exactly the same problem on 5.7.11 64-bit on Windows.

My table has many records, but it happens only to 1 record (length: 98835 chars), even other records are longer (max length: 204577 chars). After localizing the affected record, I dupplicated it to another table (using CREATE TABLE .. AS SELECT), and it also happens to the new table (with only 1 record and 1 column).

I can't select from the Command Prompt client. I also can't using mysqldump to export the data.

However, if I use a script in PHP, then I can retreive the data without problem.

Same problem with 6.3.7 on OSX, both El Captain and Sierra
When ssh is used, 90% of the time query will hang on select if ssh tunnel is used to connect to MySQL. Problem exists with 5.6.30 and 5.7.14 servers (Linux). Doesn't depend on number of rows requested or packet size. Hangs with or without WAN compression.
This problem renders workbench practically unusable!!

Bug #83352 marked as duplicate of this

Bug #84334 marked as duplicate of this

Posted by developer:
 
When running large queries over an SSH tunnel, MySQL Workbench became unresponsive.

Posted by developer:
 
Fixed as of the upcoming MySQL Workbench 6.3.9 release, and here's the changelog entry:

When running large queries over an SSH tunnel, MySQL Workbench became
unresponsive.

Thank you for the bug report.

http://bugs.mysql.com/bug.php?id=87014  marked as duplicate of this one.