Today, I noticed that one of my machines was giving a negative
number for threads connected.
Anyone care to share why the threads would be displayed as a
negative number in mysqladmin ex output:
| Aborted_connects | 0 |
| Connections | 186 |
| Max_used_connections | 0 |
| Threads_connected | -31 |
| Aborted_connects | 0 |
I grew up on a farm. Lest anyone automatically load up their
preconceived notions of farmers, my Dad was (and is) very
interested in computers and purchased the original IBM PC back in
the early/mid 80's. He found a lot of practical use in the Lotus
1-2-3 spreadsheet program, and could fly through the keyboard
shortcuts (I guess they weren't really shortcuts in those days,
as there wasn't a mouse) fast enough to put him on the same level
with any Unix geek today with Emacs or Vi.
In the 90's, I remember him buying our 486/66
with 16MB of RAM from Micron and describing it as a computer that
would "peel out on the lawn." My dad is a tractor-guy and has
always been obsessed with horsepower. He still likes to rev up
his …
For the mysql-proxy I'm exploring several ways to write a small SQL parser for the internal commands. As I want to use basic SQL to modify the config and the internal operations I need a parser. Some time ago I used lemon which is used in sqlite3, which is easier to use than yacc, but you still have to write the lexer/tokenizer.
This time I looked into ragel which is a state-machine compiler.
Time get rid of code like this:
....
} else if (0 == g_ascii_strncasecmp(s->str + NET_HEADER_SIZE + 1,
C("update proxy_config set value=0 where option=\"proxy.profiling\""))) {
....
Ragel is a bit different than lex/yacc. Ragel combines the two into one and builds a full state-machine for the input stream. Just one file, one state-machine for the parser and lexer.
%%{
machine sql;
SELECT = /SELECT/i;
FROM = /FROM/i;
WHERE = …[Read more]
It's not new (Yahoo! Pipes is already there) but the Visual Studio integration is the kicker. Check it out: http://www.popfly.ms/Overview/
Hi,
MySQL Connector/Net 5.0.7 a new version of the all-managed .NET driver for MySQL has been released.
This is a bug fix release for the current production branch of Connector/Net.
Version 5.0.7 is suitable for use with any MySQL version including MySQL-4.1, MySQL-5.0, MySQL-5.1 beta or the MySQL-6.0 Falcon "Preview".
It is now available in source and binary form from the Connector/Net download pages at http://dev.mysql.com/downloads/connector/net/5.0.html and mirror sites (note that not all mirror sites may be up to date at this point of time - if you can't find this version on some mirror, please try again later or choose another download site.)
Bugs fixed
So if you like to try out new things, and you're not using VMWare yet, get with the program!Really, though - it's so easy now (and the VMServer is free) . Just download and install.VMWare lets you run mini virtualized server environments within your current operating system. Yea, there is a little overhead, but for testing and trying out new databases, configurations, applications, it's
It's not new (Yahoo! Pipes is already there) but the Visual Studio integration is the kicker. Check it out: http://www.popfly.ms/Overview/
The excellent Doug Burns has published the 45th edition of Log Buffer, the weekly review of database blogs, on Doug’s Oracle Blog. Log Buffer thrives on the contributions of editors such as Doug and all the rest, and its dance-card is currently wide-open. If you’d like to draw some new readers to your blog, try [...]
When I first joined MySQL one of the things that was evident was the Support Engineers spent quite some time with customers issues that were focused on performance tuning. Performance tuning issues generally start with a engineer requesting a bunch of information from the customer such as:
A lot of this output is pretty easy to go through when you know what you are looking for. However where we spend a lot of our time is looking through the SHOW GLOBAL STATUS output - trying to piece together the rates of change etc. so that we can get more insight in to what is hurting the database.
I also …
[Read more]
Having discussed BLOB streaming for MySQL with a number of people
I have gathered quite a bit of input on the subject.
So here are some details of the issues raised so far:
Server-side API
One of the first things that Brian Aker pointed out to me was
that the server-side API must make it possible to use the
sendfile() system call. The call does direct disk to network
transfer and can speed up delivery of a BLOB stream
significantly.
The server-side API must also include a mechanism to inform the
stream enabled engine that an upload is complete. Assuming the
streaming protocol used is HTTP, there are 2 ways of determining
the end of a download: either the connection is closed when
download is complete, or the length of the BLOB data is specified
in a HTTP header.
ODBC Issues
Monty was concerned about compatibility with the MySQL ODBC
driver. The …