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Add material about postmaster startup failure messages;

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update material about client connection failure messages.
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Tom Lane 1999-05-21 02:42:59 +00:00
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commit a1d9186067
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doc/src/sgml/trouble.sgml
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<Title>Troubleshooting</Title>
<sect1>
<title>Client Connections</title>
<Para>
If you get the following error message from a
<ProductName>Postgres</ProductName>
command (such as <Application>psql</Application> or
<Application>createdb</Application>):
<title>Postmaster Startup Failures</title>
<para>
There are several common reasons for the postmaster to fail to start up.
Check the postmaster's log file, or start it by hand (without redirecting
standard output or standard error) to see what complaint messages appear.
Some of the possible error messages are reasonably self-explanatory,
but here are some that are not:
</para>
<para>
<ProgramListing>
connectDB() failed: Is the postmaster running at 'localhost' on port '5432'?
FATAL: StreamServerPort: bind() failed: Address already in use
Is another postmaster already running on that port?
</ProgramListing>
it is usually because either the <Application>postmaster</Application> is not running,
or you are attempting to connect to the wrong server host.
If you get the following error message:
This usually means just what it suggests: you accidentally started a
second postmaster on the same port where one is already running.
However, if the kernel error
message is not "Address already in use" or some variant of that wording,
there may be a different problem. For example, trying to start a
postmaster on a reserved port number may draw something like
<ProgramListing>
FATAL 1:Feb 17 23:19:55:process userid (2360) != database owner (268)
$ postmaster -i -p 666
FATAL: StreamServerPort: bind() failed: Permission denied
Is another postmaster already running on that port?
</ProgramListing>
</para>
<para>
<ProgramListing>
IpcMemoryCreate: shmget failed (Invalid argument) key=5440001, size=83918612, permission=600
FATAL 1: ShmemCreate: cannot create region
</ProgramListing>
A message like this probably means that your kernel's limit on the size
of shared memory areas is smaller than the buffer area that Postgres
is trying to create. (Or it could mean that you don't have SysV-style
shared memory support configured into your kernel at all.) As a temporary
workaround, you can try starting the postmaster with a smaller-than-normal
number of buffers (-B switch). You will eventually want to reconfigure
your kernel to increase the allowed shared memory size, however.
You may see this message when trying to start multiple postmasters on
the same machine, if their total space requests exceed the kernel limit.
</para>
<para>
<ProgramListing>
IpcSemaphoreCreate: semget failed (No space left on device) key=5440026, num=16, permission=600
</ProgramListing>
A message like this does <emphasis>not</emphasis> mean that you've run out
of disk space; it means that your kernel's limit on the number of SysV
semaphores is smaller than the number Postgres wants to create. As above,
you may be able to work around the problem by starting the postmaster with
a reduced number of backend processes (-N switch), but you'll eventually
want to increase the kernel limit.
</para>
</sect1>
<sect1>
<title>Client Connection Problems</title>
<para>
Once you have a running postmaster, trying to connect to it with
client applications can fail for a variety of reasons. The sample
error messages shown here are for clients based on recent versions
of libpq --- clients based on other interface libraries may produce
other messages with more or less information.
</para>
<para>
<ProgramListing>
connectDB() -- connect() failed: Connection refused
Is the postmaster running (with -i) at 'server.joe.com' and accepting connections on TCP/IP port '5432'?
</ProgramListing>
This is the generic "I couldn't find a postmaster to talk to" failure.
It looks like the above when TCP/IP communication is attempted, or like
this when attempting Unix-socket communication to a local postmaster:
<ProgramListing>
connectDB() -- connect() failed: No such file or directory
Is the postmaster running at 'localhost' and accepting connections on Unix socket '5432'?
</ProgramListing>
The last line is useful in verifying that the client is trying to connect
where it is supposed to. If there is in fact no postmaster
running there, the kernel error message will typically be either
"Connection refused" or "No such file or directory", as illustrated.
(It is particularly important to realize that "Connection refused" in
this context does <emphasis>not</emphasis> mean that the postmaster
got your connection request and rejected it --- that case will produce
a different message, as shown below.)
Other error messages such as "Connection timed out" may indicate more
fundamental problems, like lack of network connectivity.
</para>
<para>
<ProgramListing>
No pg_hba.conf entry for host 123.123.123.123, user joeblow, database testdb
</ProgramListing>
This is what you are most likely to get if you succeed in contacting
a postmaster, but it doesn't want to talk to you. As the message
suggests, the postmaster refused the connection request because it
found no authorizing entry in its pg_hba.conf configuration file.
</para>
<para>
<ProgramListing>
Password authentication failed for user 'joeblow'
</ProgramListing>
Messages like this indicate that you contacted the postmaster, and it's
willing to talk to you, but not until you pass the authorization method
specified in the pg_hba.conf file. Check the password you're providing,
or check your Kerberos or IDENT software if the complaint mentions
one of those authentication types.
</para>
<para>
<ProgramListing>
FATAL 1: SetUserId: user 'joeblow' is not in 'pg_shadow'
</ProgramListing>
This is another variant of authentication failure: no Postgres create_user
command has been executed for the given username.
</para>
<para>
<ProgramListing>
FATAL 1: Database testdb does not exist in pg_database
</ProgramListing>
There's no database by that name under the control of this postmaster.
Note that if you don't specify a database name, it defaults to your
Postgres username, which may or may not be the right thing.
</para>
it means that the site administrator started the <Application>postmaster</Application>
as the wrong user. Tell him to restart it as
the <ProductName>Postgres</ProductName> superuser.
</Para>
</sect1>
<sect1>