Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thursday, September 14, 2017, Robert Haas wrote: > On Thu, Sep 14, 2017 at 3:23 AM, Tsunakawa, Takayuki > > wrote: > > Sorry again, but how can we handle this? A non-PG-developer, Tels (and > possibly someone else, IIRC)

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thu, May 18, 2017 at 8:11 PM, Michael Paquier wrote: > On Thu, May 18, 2017 at 11:30 PM, Robert Haas wrote: >> On Thu, May 18, 2017 at 7:06 AM, Michael Paquier >> wrote: >>> FWIW, I am of the opinion to not have an

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thu, May 18, 2017 10:24 pm, Tsunakawa, Takayuki wrote: > From: pgsql-hackers-ow...@postgresql.org >> [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Michael >> Paquier >> On Thu, May 18, 2017 at 11:30 PM, Robert Haas >> wrote: >> > Because why? >> >> Because it

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Michael Paquier > > One thing I'm worried is that people here might become more conservative > against change once the final version is released. > > Any redesign after release would finish by

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Michael Paquier > On Thu, May 18, 2017 at 11:30 PM, Robert Haas wrote: > > Because why? > > Because it is critical to let the user know as well *why* an error happened. >

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Fri, May 19, 2017 at 11:01 AM, Tsunakawa, Takayuki wrote: > From: pgsql-hackers-ow...@postgresql.org >> [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Peter Eisentraut >> The problem is that if we decide to change the behavior mid-beta, then we'll >>

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Peter Eisentraut > The problem is that if we decide to change the behavior mid-beta, then we'll > only have the rest of beta to find out whether people will like the other > behavior. > > I would

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On 5/17/17 13:19, Tom Lane wrote: > I agree with Robert's point that major redesign of the feature on the > basis of one complaint isn't necessarily the way to go. Since the > existing behavior is already out in beta1, let's wait and see if anyone > else complains. We don't need to fix it Right

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thu, May 18, 2017 at 11:30 PM, Robert Haas wrote: > On Thu, May 18, 2017 at 7:06 AM, Michael Paquier > wrote: >> FWIW, I am of the opinion to not have an implementation based on any >> SQLSTATE codes, as well as not doing something similar to

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thu, May 18, 2017 at 7:06 AM, Michael Paquier wrote: > FWIW, I am of the opinion to not have an implementation based on any > SQLSTATE codes, as well as not doing something similar to JDBC. > Keeping things simple is one reason, a second is that the approach > taken

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thu, May 18, 2017 at 5:05 PM, Tsunakawa, Takayuki wrote: > So, how about trying connection to the next host when the class code is > neither 28, 3D, nor 42? > > Honestly, I'm not happy with this approach, for a maintenance reason that > others are worried

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Tsunakawa, > Takayuki > Done. I'll examine whether we can use SQLSTATE. I tried conceivable errors during connection. Those SQLSTATEs are as follows: [transient error (after which you may want

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: Michael Paquier [mailto:michael.paqu...@gmail.com] > Does JDBC use something like that to make a difference between a failure > and a move-on-to-next-one? No, it just tries the next host. See the first while loop in org/postgresql/jdbc/core/v3/ConnectionFactoryImpl.java. > From

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Thu, May 18, 2017 at 12:07 PM, Tsunakawa, Takayuki wrote: > From: Tom Lane [mailto:t...@sss.pgh.pa.us] >> Maybe add this to the list of open issues to reconsider mid-beta? > > Done. I'll examine whether we can use SQLSTATE. Does JDBC use something like that to

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: Tom Lane [mailto:t...@sss.pgh.pa.us] > Sure, but part of the point of beta testing is to get user feedback. Yes, and I'm also proposing this in the user's point of view, which I believe holds true for people here. I'm worried from my support experience that strict customers would

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Moin, On Wed, May 17, 2017 12:34 pm, Robert Haas wrote: > On Wed, May 17, 2017 at 3:06 AM, Tsunakawa, Takayuki > wrote: >> What do you think of the following cases? Don't you want to connect to >> other servers? >> >> * The DBA shuts down the database. The

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Tom, * Tom Lane (t...@sss.pgh.pa.us) wrote: > I agree with Robert's point that major redesign of the feature on the > basis of one complaint isn't necessarily the way to go. Since the > existing behavior is already out in beta1, let's wait and see if anyone > else complains. We don't need to

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Wed, May 17, 2017 at 12:06 AM, Tsunakawa, Takayuki < tsunakawa.ta...@jp.fujitsu.com> wrote: > From: pgsql-hackers-ow...@postgresql.org > > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Robert Haas > > Who is right is a judgement call, but I don't think it's self-evident > that > >

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Stephen Frost writes: > * Robert Haas (robertmh...@gmail.com) wrote: >> One good argument for leaving this alone entirely is that this feature >> was committed on November 3rd and this thread began on May 12th. If >> there was ample time before feature freeze to question the

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Robert, * Robert Haas (robertmh...@gmail.com) wrote: > One good argument for leaving this alone entirely is that this feature > was committed on November 3rd and this thread began on May 12th. If > there was ample time before feature freeze to question the design and > nobody did, then I'm not

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Wed, May 17, 2017 at 12:48 PM, Tom Lane wrote: > Robert Haas writes: >> Yeah, you have a point. I'm willing to admit that we may have defined >> the behavior of the feature incorrectly, provided that you're willing >> to admit that you're proposing

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Stephen Frost writes: > * Tom Lane (t...@sss.pgh.pa.us) wrote: >> I suggest that we need to conditionalize the decision based on what >> SQLSTATE is reported. Not sure offhand if it's better to have a whitelist >> of SQLSTATEs that allow failing over to the next server, or a

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Tom, Robert, * Tom Lane (t...@sss.pgh.pa.us) wrote: > Robert Haas writes: > > Yeah, you have a point. I'm willing to admit that we may have defined > > the behavior of the feature incorrectly, provided that you're willing > > to admit that you're proposing a definition

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Robert Haas writes: > Yeah, you have a point. I'm willing to admit that we may have defined > the behavior of the feature incorrectly, provided that you're willing > to admit that you're proposing a definition change, not just a bug > fix. > Anybody else want to weigh in

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Wed, May 17, 2017 at 3:06 AM, Tsunakawa, Takayuki wrote: > What do you think of the following cases? Don't you want to connect to other > servers? > > * The DBA shuts down the database. The server takes a long time to do > checkpointing. During the shutdown

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Hello Robert, Tom, Thank you for being kind enough to explain. I think I could understand your concern. From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Robert Haas > Who is right is a judgement call, but I don't think it's self-evident that >

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Robert Haas writes: > On Sun, May 14, 2017 at 9:50 PM, Tsunakawa, Takayuki > wrote: >> By the way, could you elaborate what problem could occur if my solution is >> applied? (it doesn't seem easy for me to imagine...) > Sure. Imagine

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Sun, May 14, 2017 at 9:50 PM, Tsunakawa, Takayuki wrote: >> I guess not as well. That would be tricky for the user to have a different >> behavior depending on the error returned by the server, which is why the >> current code is doing things right IMO. Now, the

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: Michael Paquier [mailto:michael.paqu...@gmail.com] > On Fri, May 12, 2017 at 10:44 PM, Tom Lane wrote: > > I would not really expect that reconnection would retry after > > arbitrary failure cases. Should it retry for "wrong database name", for > instance? > > It's not

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Sun, May 14, 2017 at 9:19 PM, Michael Paquier wrote: > On Fri, May 12, 2017 at 10:44 PM, Tom Lane wrote: >> Michael Paquier writes: >>> On Fri, May 12, 2017 at 1:28 PM, Tsunakawa, Takayuki >>>

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Fri, May 12, 2017 at 10:44 PM, Tom Lane wrote: > Michael Paquier writes: >> On Fri, May 12, 2017 at 1:28 PM, Tsunakawa, Takayuki >> wrote: >>> Likewise, when the first host has already reached max_connections,

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Michael Paquier writes: > On Fri, May 12, 2017 at 1:28 PM, Tsunakawa, Takayuki > wrote: >> Likewise, when the first host has already reached max_connections, libpq >> doesn't attempt the connection aginst later hosts. > It seems to me

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

From: Michael Paquier [mailto:michael.paqu...@gmail.com] > It seems to me that the feature is behaving as wanted. Or in short attempt > to connect to the next host only if a connection cannot be established. > If there is a failure once the exchange with the server has begun, just > consider it as

Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

On Fri, May 12, 2017 at 1:28 PM, Tsunakawa, Takayuki wrote: > Likewise, when the first host has already reached max_connections, libpq > doesn't attempt the connection aginst later hosts. It seems to me that the feature is behaving as wanted. Or in short attempt

[HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Hello, I found a problem with libpq connection failover. When libpq cannot connect to earlier hosts in the host list, it doesn't try to connect to other hosts. For example, when you specify a wrong port that some non-postgres program is using, or some non-postgres program is using PG's port