I am fairly new to MYSQL but I can't locate the answer in either the
config file or my books. It is probably there but hasn't jumped out at me
yet. Two problems actually.

I can access the database with the address of www-data@localhost, but not
with username and the actual hostname - i.e www-data@altair. (No domain -
this is on a private network). The messages says that the DB doesn't exist
on www-data@altair, even though it does.

Not really a problem except that www-data@localhost is not accepted
because the length exceeds 16 characters. www-data@altair is legal, but
MYSQL doesn't map the local hostname..

And the 16 character limit is really surprising, since any user name over
7 characters is invalid, which is most user names. Or am I missing
something?

I can and have worked around the above, but would like to understand some
more of what is happening.

Anybody?

keersarge

On Fri, 02 Nov 2007 16:33:38 -0000, keersarge wrote:

> I am fairly new to MYSQL but I can't locate the answer in either the
> config file or my books. It is probably there but hasn't jumped out at
> me yet. Two problems actually.
>
> I can access the database with the address of www-data@localhost, but
> not with username and the actual hostname - i.e www-data@altair. (No
> domain - this is on a private network). The messages says that the DB
> doesn't exist on www-data@altair, even though it does.

Quote the message exactly, please. I don't think it is saying what you
think it's saying.

> Not really a problem except that www-data@localhost is not accepted
> because the length exceeds 16 characters. www-data@altair is legal,
> but MYSQL doesn't map the local hostname..
>
> And the 16 character limit is really surprising, since any user name
> over 7 characters is invalid, which is most user names. Or am I
> missing something?

'www-data' is the user name. The rest is host information. The user name
part is limited to 16 characters. The total isn't. One of the user
entries on my system is 'gallery@gehenna.ninehells.com', which is rather
more than 16 characters.

--
I think I'd like to see a Simpsons episode starting up with Bart Simpson
writing "I will not attempt to undermine the Usenet Cabal".
-- J. D. Falk

Ok, my fault. I should have given hard info rather than just questions.
One thing at a time. I am still working on my address length question and
may have the answer - I think.

But back to the connect problem.

>> I can access the database with the address of www-data@localhost, but
>> not with username and the actual hostname - i.e www-data@altair. (No
>> domain - this is on a private network). The messages says that the DB
>> doesn't exist on www-data@altair, even though it does.
>
> Quote the message exactly, please. I don't think it is saying what you
> think it's saying.
>
>
On my learning server, the host name is now 'Sol' with an address of
192.168.0.15 and the hostname is in the /etc/hosts file. I can ping
it from a client on the same private network by name or number so it is
resolving the name ok.

I am calling it with a perl script, but I also tried with a manual line by
line access and get the same stuff.

Here is the perl string calling the connect... #
$dbh = DBI->connect("DBI:mysql:database=draco;host=Sol", "www-data",
"testpass");

and the error in the log...

DBI connect('database=draco;host=Sol','www-data',...) failed: Can't connect
to MySQL server on 'Sol' (111) at /usr/lib/cgi-bin/neworder.pl line 190

####################

But if I change it to the following...
$dbh = DBI->connect("DBI:mysql:database=draco;host=localhost" ,
"www-data", "testpass");

it connects to the DB and no error in the log. Insert and query data just
fine.

#####################

So to recap, www-data@Sol doesn't connect but www-data@localhost does.
The example is straight out of the book, except for my names and addresses
so I think I am missing a configuration line somewhere to resolve a real
address.

Again, using localhost will work fine, but I am trying to learn rather
than write production code, so I try to run down all not-understood
defugalties.

Thanks for the reply
keersarge

keersarge wrote:
> Ok, my fault. I should have given hard info rather than just
> questions. One thing at a time. I am still working on my address
> length question and may have the answer - I think.
>
> But back to the connect problem.
>
>>> I can access the database with the address of www-data@localhost,
>>> but not with username and the actual hostname - i.e
>>> www-data@altair. (No domain - this is on a private network). The
>>> messages says that the DB doesn't exist on www-data@altair, even
>>> though it does.
>>
>> Quote the message exactly, please. I don't think it is saying what
>> you think it's saying.
>>
>>
> On my learning server, the host name is now 'Sol' with an address of
> 192.168.0.15 and the hostname is in the /etc/hosts file. I can ping
> it from a client on the same private network by name or number so it
> is resolving the name ok.
>
> I am calling it with a perl script, but I also tried with a manual
> line by line access and get the same stuff.
>
> Here is the perl string calling the connect... #
> $dbh = DBI->connect("DBI:mysql:database=draco;host=Sol", "www-data",
> "testpass");
>
> and the error in the log...
>
> DBI connect('database=draco;host=Sol','www-data',...) failed: Can't
> connect to MySQL server on 'Sol' (111) at
> /usr/lib/cgi-bin/neworder.pl line 190
>
> ####################
>
> But if I change it to the following...
> $dbh = DBI->connect("DBI:mysql:database=draco;host=localhost" ,
> "www-data", "testpass");
>
> it connects to the DB and no error in the log. Insert and query data
> just fine.
>
> #####################
>
> So to recap, www-data@Sol doesn't connect but www-data@localhost does.
> The example is straight out of the book, except for my names and
> addresses so I think I am missing a configuration line somewhere to
> resolve a real address.
>
> Again, using localhost will work fine, but I am trying to learn rather
> than write production code, so I try to run down all not-understood
> defugalties.
>
> Thanks for the reply
> keersarge

This sounds like the query discussed recently in this group entitled "Are
these 3 hosts not the same thing?"

But can you post the message that said that the DB did not exist on
www-data@altair, that yo mentioned earlier?

>Ok, my fault. I should have given hard info rather than just questions.
>One thing at a time. I am still working on my address length question and
>may have the answer - I think.
>
>But back to the connect problem.
>
>>> I can access the database with the address of www-data@localhost, but
>>> not with username and the actual hostname - i.e www-data@altair. (No
>>> domain - this is on a private network). The messages says that the DB
>>> doesn't exist on www-data@altair, even though it does.

The error message below does not say the DB doesn't exist, it says
it can't connect to the server. These are very different errors.

>>
>> Quote the message exactly, please. I don't think it is saying what you
>> think it's saying.
>>
>>
>On my learning server, the host name is now 'Sol' with an address of
>192.168.0.15 and the hostname is in the /etc/hosts file. I can ping
>it from a client on the same private network by name or number so it is
>resolving the name ok.

Can you "ping Sol" *from the machine you are running the client on* (Sol)?

>I am calling it with a perl script, but I also tried with a manual line by
>line access and get the same stuff.
>
>Here is the perl string calling the connect... #
> $dbh = DBI->connect("DBI:mysql:database=draco;host=Sol", "www-data",
> "testpass");
>
>and the error in the log...
>
>DBI connect('database=draco;host=Sol','www-data',...) failed: Can't connect
>to MySQL server on 'Sol' (111) at /usr/lib/cgi-bin/neworder.pl line 190
>
>####################
>
>But if I change it to the following...
> $dbh = DBI->connect("DBI:mysql:database=draco;host=localhost" ,
> "www-data", "testpass");

Does it work if you change localhost to 127.0.0.1?

If it works only with localhost (which uses a local socket), and not
with 127.0.0.1 (which uses TCP/IP), this suggests the possibilities:
- You started the MySQL server with --skip-networking.
- You have a firewall preventing incoming connections on the MySQL port
(default 3306).
- The client and the server don't agree on what port to use (if it's the
default on both, they should agree).
- You failed to GRANT permissions to www-data@Sol or www-data@127.0.0.1 .
Although I don't think this is your problem YET, it may be the next one
when you fix the current problem.

>it connects to the DB and no error in the log. Insert and query data just
>fine.
>
>#####################
>
>So to recap, www-data@Sol doesn't connect but www-data@localhost does.
>The example is straight out of the book, except for my names and addresses
>so I think I am missing a configuration line somewhere to resolve a real
>address.

> But can you post the message that said that the DB did not exist on
> www-data@altair, that yo mentioned earlier?

Sorry, no. Not the original. That machine has been reloaded several
times since then. It's a learning machine that I try different stuff on.

I can probably create the same error in its current reincarnation, though.

keersarge

> Can you "ping Sol" *from the machine you are running the client on*
> (Sol)?
>
Yes, no problem. Since it is headless, I also use ssh and scp for
all work on it. My client has Sol in the /etc/hosts file and resolves
the name ok. NFS resolves and works with Sol just fine. So as far as
Linux is concerned, it is a normal server.



> Does it work if you change localhost to 127.0.0.1?
>
Hmmm. I will try that when I get back home.

> If it works only with localhost (which uses a local socket), and not
> with 127.0.0.1 (which uses TCP/IP), this suggests the possibilities: -
> You started the MySQL server with --skip-networking. - You have a
> firewall preventing incoming connections on the MySQL port
> (default 3306).

No firewall between them. All machines are Debian. Mostly Sarge but being
upgraded to Etch.

> - The client and the server don't agree on what port to use (if it's the
> default on both, they should agree).

Being an absolute noob with MYSQL at the moment, I took all defaults on
installation. In fact, I just did an "apt-get install mysql-server" and it
worked. I have changed no conf files yet and have not played with option
files.


> - You failed to GRANT permissions to www-data@Sol or www-data@127.0.0.1

GRANT ALL PRIVILEGES ON *.* TO 'www-data@sol'; and
GRANT ALL PRIVILEGES ON *.* TO 'krf@localhost';

gave me a successful reply on both.

> .
> Although I don't think this is your problem YET, it may be the next
> one when you fix the current problem.
>

I have no doubt that many issues are ahead as I learn, but the books are
good and so is the online advice.

Thanks
keersarge

keersarge wrote:
>> But can you post the message that said that the DB did not exist on
>> www-data@altair, that yo mentioned earlier?
>
> Sorry, no. Not the original. That machine has been reloaded several
> times since then. It's a learning machine that I try different stuff
> on.
>
> I can probably create the same error in its current reincarnation,
> though.
>
> keersarge

Did you look at the thread that I mentioned in my post?

On Fri, 02 Nov 2007 23:00:24 -0000, keersarge wrote:
> $dbh = DBI->connect("DBI:mysql:database=draco;host=Sol", "www-data",
> "testpass");
>
> and the error in the log...
>
> DBI connect('database=draco;host=Sol','www-data',...) failed: Can't connect
> to MySQL server on 'Sol' (111) at /usr/lib/cgi-bin/neworder.pl line 190

This looks like a connection failure, not an authorization error of some
kind.

>
> ####################
>
> But if I change it to the following...
> $dbh = DBI->connect("DBI:mysql:database=draco;host=localhost" ,
> "www-data", "testpass");
>
> it connects to the DB and no error in the log. Insert and query data just
> fine.
>
> #####################
>
> So to recap, www-data@Sol doesn't connect but www-data@localhost does.
> The example is straight out of the book, except for my names and addresses
> so I think I am missing a configuration line somewhere to resolve a real
> address.

@sol means "try a network socket connection" to the mysql libraries, and
@localhost means "use the unix socket connection". Which means you're
succeeding via the unix socket, but failing via network. This is *in
spite of* the usual thinking that "localhost" means "network to
127.0.0.1".


> Again, using localhost will work fine, but I am trying to learn rather
> than write production code, so I try to run down all not-understood
> defugalties.

Make sure you've enabled networking. Try telneting to that machine to
port 3306.

$ telnet 127.0.0.1 3306
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
8
5.0.33-logû5IQ=xj)-,ERNn_q>|yl0GConnection closed by foreign host.

That's a live MySQL server. Note the version number '5.0.33-log'.
"Connection refused" is not a MySQL server.

--
_ o
|/)