Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Tom Lane wrote: Bruce Momjian br...@momjian.us writes: Tom Lane wrote: PQping is supposed to be smarter about classifying errors than this. I was not aware this was discussed last week because I am behind on email. I was fixing a report from a month ago. I did explain how I was doing the tests. Um, you did respond in that thread, several times even: http://archives.postgresql.org/pgsql-hackers/2010-11/msg01102.php so I kind of assumed that the patch you presented this week did what was agreed to last week. Yes, I do remember that, but I remember this: http://archives.postgresql.org/pgsql-hackers/2010-11/msg01095.php What we want here is to check the result of postmaster.c's canAcceptConnections(), and this: http://archives.postgresql.org/pgsql-hackers/2010-11/msg01106.php You do have to distinguish connection failures (ie connection refused) from errors that came back from the postmaster, and the easiest place to be doing that is inside libpq. which I thought meant it had to be done in libpq and we didn't have access to the postmaster return codes in libpq. Your changes look very good, and not something I would have been able to code. I have committed a patch to make PQping do what was agreed to. Thanks. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Fujii Masao wrote: On Fri, Nov 26, 2010 at 3:11 AM, Bruce Momjian br...@momjian.us wrote: I have applied this patch, with modified wording of the cannot connect case: ? ? ? ?$ pg_ctl -w -l /dev/null start ? ? ? ?waiting for server to start done ? ? ? ?server started ? ? ? ?warning: ?could not connect, perhaps due to invalid authentication or ? ? ? ?misconfiguration. This patch breaks the behavior that pg_ctl -w start waits until the standby has been ready to accept read-only queries. IOW, pg_ctl without this patch continues to check the connection even if the connection is rejected because the database has not been consistent yet. But pg_ctl with this patch treats that rejection as success of the standby starting and prints the above messages. I agree to treat the receipt of password request from the server as success of the server starting. But I don't think that we should treat other rejection cases that way and change the existing behavior. OK, that is easy to fix. The only downside is that if you misconfigured .pgpass (which is what I used for testing), you have to wait 60 seconds to get the cannot connect error message. Is that OK? -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Hey hackers, I am sorry, but is it possible to implement BTW ability to check exactly status of authentication from libpq ? As for now, the only way to check failed authentication is parsing the error message, that is sadly. 2010/11/26 Bruce Momjian br...@momjian.us Fujii Masao wrote: On Fri, Nov 26, 2010 at 3:11 AM, Bruce Momjian br...@momjian.us wrote: I have applied this patch, with modified wording of the cannot connect case: ? ? ? ?$ pg_ctl -w -l /dev/null start ? ? ? ?waiting for server to start done ? ? ? ?server started ? ? ? ?warning: ?could not connect, perhaps due to invalid authentication or ? ? ? ?misconfiguration. This patch breaks the behavior that pg_ctl -w start waits until the standby has been ready to accept read-only queries. IOW, pg_ctl without this patch continues to check the connection even if the connection is rejected because the database has not been consistent yet. But pg_ctl with this patch treats that rejection as success of the standby starting and prints the above messages. I agree to treat the receipt of password request from the server as success of the server starting. But I don't think that we should treat other rejection cases that way and change the existing behavior. OK, that is easy to fix. The only downside is that if you misconfigured .pgpass (which is what I used for testing), you have to wait 60 seconds to get the cannot connect error message. Is that OK? -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers -- // Dmitriy.
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian br...@momjian.us writes: Fujii Masao wrote: I agree to treat the receipt of password request from the server as success of the server starting. But I don't think that we should treat other rejection cases that way and change the existing behavior. OK, that is easy to fix. It's wrong though. If you get back a password rejected error, or most other types of errors, it still indicates that the server started. We just went over this a few days ago. The only downside is that if you misconfigured .pgpass (which is what I used for testing), you have to wait 60 seconds to get the cannot connect error message. Is that OK? No; it's useless and unnecessary behavior. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian br...@momjian.us writes: Fujii Masao wrote: This patch breaks the behavior that pg_ctl -w start waits until the standby has been ready to accept read-only queries. IOW, pg_ctl without this patch continues to check the connection even if the connection is rejected because the database has not been consistent yet. But pg_ctl with this patch treats that rejection as success of the standby starting and prints the above messages. The reason this is a problem is that somebody, in a fit of inappropriate optimization, took out the code that allowed canAcceptConnections to distinguish the not consistent yet state. We need to put that back, not try to kluge around the problem from the client side. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
I wrote: The reason this is a problem is that somebody, in a fit of inappropriate optimization, took out the code that allowed canAcceptConnections to distinguish the not consistent yet state. Oh, no, that's not the case --- the PM_RECOVERY postmaster state does still distinguish not-ready from ready. The real problem is that what Bruce implemented has practically nothing to do with what was discussed last week. PQping is supposed to be smarter about classifying errors than this. Speaking of classifying errors, should we have a fourth result value to cover obviously bogus parameters? Right now you'll get PQNORESPONSE for cases like incorrect syntax in the conninfo string. I'm not sure how tense we ought to try to be about distinguishing, but if libpq failed before even attempting a connection, PQNORESPONSE seems a bit misleading. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Nov 26, 2010 at 6:30 PM, Tom Lane t...@sss.pgh.pa.us wrote: Speaking of classifying errors, should we have a fourth result value to cover obviously bogus parameters? +1. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Tom Lane wrote: I wrote: The reason this is a problem is that somebody, in a fit of inappropriate optimization, took out the code that allowed canAcceptConnections to distinguish the not consistent yet state. Oh, no, that's not the case --- the PM_RECOVERY postmaster state does still distinguish not-ready from ready. The real problem is that what Bruce implemented has practically nothing to do with what was discussed last week. PQping is supposed to be smarter about classifying errors than this. I was not aware this was discussed last week because I am behind on email. I was fixing a report from a month ago. I did explain how I was doing the tests. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian br...@momjian.us writes: Tom Lane wrote: PQping is supposed to be smarter about classifying errors than this. I was not aware this was discussed last week because I am behind on email. I was fixing a report from a month ago. I did explain how I was doing the tests. Um, you did respond in that thread, several times even: http://archives.postgresql.org/pgsql-hackers/2010-11/msg01102.php so I kind of assumed that the patch you presented this week did what was agreed to last week. I have committed a patch to make PQping do what was agreed to. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian wrote: BTW, it is annoying that we can't definitively distinguish postmaster is not running from a connectivity problem, but I can't see a way around that. Agreed. I will research this. I have researched this and developed the attached patch. It implements PGping() and PGpingParams() in libpq, and has pg_ctl use it for pg_ctl -w server status detection. The new output for cases where .pgpass is not allowing for a connection is: $ pg_ctl -w -l /dev/null start waiting for server to start done server started However, could not connect, perhaps due to invalid authentication or misconfiguration. The code basically checks the connection status between PQconnectStart() and connectDBComplete() to see if the server is running but we failed to connect for some reason. I have applied this patch, with modified wording of the cannot connect case: $ pg_ctl -w -l /dev/null start waiting for server to start done server started warning: could not connect, perhaps due to invalid authentication or misconfiguration. I assume having the warning as the last printed things is appropriate. This is my second patch this week that got little feedback --- I am getting a little spooked. ;-) -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Nov 26, 2010 at 3:11 AM, Bruce Momjian br...@momjian.us wrote: I have applied this patch, with modified wording of the cannot connect case: $ pg_ctl -w -l /dev/null start waiting for server to start done server started warning: could not connect, perhaps due to invalid authentication or misconfiguration. This patch breaks the behavior that pg_ctl -w start waits until the standby has been ready to accept read-only queries. IOW, pg_ctl without this patch continues to check the connection even if the connection is rejected because the database has not been consistent yet. But pg_ctl with this patch treats that rejection as success of the standby starting and prints the above messages. I agree to treat the receipt of password request from the server as success of the server starting. But I don't think that we should treat other rejection cases that way and change the existing behavior. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian wrote: Tom Lane wrote: Bruce Momjian br...@momjian.us writes: Tom Lane wrote: Possibly the cleanest fix is to implement pg_ping as a libpq function. You do have to distinguish connection failures (ie connection refused) from errors that came back from the postmaster, and the easiest place to be doing that is inside libpq. OK, so a new libpq function --- got it. Would we just pass the status from the backend or can it be done without backend modifications? It would definitely be better to do it without backend mods, so that the functionality would work against back-branch postmasters. To my mind, the entire purpose of such a function is to classify the possible errors so that the caller doesn't have to. So I wouldn't consider that it ought to pass back the status from the backend. I think what we basically want is a function that takes a conninfo string (or one of the variants of that) and returns an enum defined more or less like this: * failed to connect to postmaster * connected, but postmaster is not accepting sessions * postmaster is up and accepting sessions I'm not sure those are exactly the categories we want, but something close to that. In particular, I don't know if there's any value in subdividing the not accepting sessions status --- pg_ctl doesn't really care, but other use-cases might want to tell the difference between the various canAcceptConnections failure states. BTW, it is annoying that we can't definitively distinguish postmaster is not running from a connectivity problem, but I can't see a way around that. Agreed. I will research this. I have researched this and developed the attached patch. It implements PGping() and PGpingParams() in libpq, and has pg_ctl use it for pg_ctl -w server status detection. The new output for cases where .pgpass is not allowing for a connection is: $ pg_ctl -w -l /dev/null start waiting for server to start done server started However, could not connect, perhaps due to invalid authentication or misconfiguration. The code basically checks the connection status between PQconnectStart() and connectDBComplete() to see if the server is running but we failed to connect for some reason. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index a911c50..32c58a5 100644 *** /tmp/b2EvXa_libpq.sgml Tue Nov 23 17:41:50 2010 --- doc/src/sgml/libpq.sgml Tue Nov 23 17:36:32 2010 *** int PQbackendPID(const PGconn *conn); *** 1511,1516 --- 1511,1584 /listitem /varlistentry + varlistentry id=libpq-pqpingparams + termfunctionPQpingParams/functionindextermprimaryPQpingParams///term + listitem + para +functionPQpingParams/function indicates the status of the +server. The currently recognized parameter key words are the +same as functionPQconnectParams/. + + synopsis + PGPing PQpingParams(const char **keywords, const char **values, int expand_dbname); + /synopsis + +It returns one of the following values: + +variablelist + varlistentry id=libpq-pqpingparams-pqaccess + termliteralPQACCESS/literal/term + listitem + para +The server is running and allows access. + /para + /listitem + /varlistentry + + varlistentry id=libpq-pqpingparams-pqreject + termliteralPQREJECT/literal/term + listitem + para +The server is running but rejected a connection request. + /para + /listitem + /varlistentry + + varlistentry id=libpq-pqpingparams-pqnoresponse + termliteralPQNORESPONSE/literal/term + listitem + para +The server did not respond. + /para + /listitem + /varlistentry +/variablelist + + /para + + /listitem + /varlistentry + + varlistentry id=libpq-pqping + termfunctionPQping/functionindextermprimaryPQping///term + listitem + para +Returns the status of the server. + + synopsis + PGPing PQping(const char *conninfo); + /synopsis + /para + + para +This function uses the same literalconninfo/literal parameter +key words as functionPQconnectdb/. It returns the same +values as functionPQpingParams/ above. + /para + + /listitem + /varlistentry + varlistentry id=libpq-pqconnectionneedspassword termfunctionPQconnectionNeedsPassword/functionindextermprimaryPQconnectionNeedsPassword///term listitem diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c index 14d36b5..7a5bb7a 100644 ***
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Magnus Hagander wrote: I basically report the connection error string if it starts with FATAL:. I originally tried to check for an ERRCODE_INVALID_PASSWORD error field (see // comments), but it seems there is no way to access this, i.e. PQgetResult(conn) on a connection failure is always NULL. Anyway, perhaps FATAL is a better test because it will report any major failure, not just a .pgpass one. Patch attached. Bad Bruce, using C++ comments like that :P And non-context diff ;) That comment use was to highlight that those are not for commit, but there if people want to test. As far as the diff, it seems git-external-diff isn't portable to non-Linux systems; I will post a separate email on that. Does this actually solve the *problem*, though? The problem is not what is reported on stdout/stderr, the problem is that the net result is that the server is reported as not started (by the service control manager) when it actually *is* started. In this case, stderr doesn't even go anywhere. What happens if you *don't* Ctrl-C it? I was just going to post on that. :-) Right now, it prints the FATAL and keeps printing 60 times, then says not running. Should we just exit on FATAL and output a special exit string, or say running? -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Wed, Nov 17, 2010 at 19:50, Bruce Momjian br...@momjian.us wrote: Magnus Hagander wrote: Does this actually solve the *problem*, though? The problem is not what is reported on stdout/stderr, the problem is that the net result is that the server is reported as not started (by the service control manager) when it actually *is* started. In this case, stderr doesn't even go anywhere. What happens if you *don't* Ctrl-C it? I was just going to post on that. :-) Right now, it prints the FATAL and keeps printing 60 times, then says not running. Should we just exit on FATAL and output a special exit string, or say running? From the perspective of the service control manager, it should say running. That might break other scenarios though, but i'm not sure - I think we can safely say the server is running when we try to log in and get a password failure. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Magnus Hagander wrote: On Wed, Nov 17, 2010 at 19:50, Bruce Momjian br...@momjian.us wrote: Magnus Hagander wrote: Does this actually solve the *problem*, though? The problem is not what is reported ?on stdout/stderr, the problem is that the net result is that the server is reported as not started (by the service control manager) when it actually *is* started. In this case, stderr doesn't even go anywhere. What happens if you *don't* Ctrl-C it? I was just going to post on that. ?:-) ?Right now, it prints the FATAL and keeps printing 60 times, then says not running. ?Should we just exit on FATAL and output a special exit string, or say running? From the perspective of the service control manager, it should say running. That might break other scenarios though, but i'm not sure - I think we can safely say the server is running when we try to log in and get a password failure. That was another part of the discussion. Right now we report any FATAL, so it might be a password problem, or something else, and it seems doing all FATALs is the best idea because it will catch any other cases like this. Is FATAL, in general, enough to conclude the server is running? -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Wed, Nov 17, 2010 at 19:57, Bruce Momjian br...@momjian.us wrote: Magnus Hagander wrote: On Wed, Nov 17, 2010 at 19:50, Bruce Momjian br...@momjian.us wrote: Magnus Hagander wrote: Does this actually solve the *problem*, though? The problem is not what is reported ?on stdout/stderr, the problem is that the net result is that the server is reported as not started (by the service control manager) when it actually *is* started. In this case, stderr doesn't even go anywhere. What happens if you *don't* Ctrl-C it? I was just going to post on that. ?:-) ?Right now, it prints the FATAL and keeps printing 60 times, then says not running. ?Should we just exit on FATAL and output a special exit string, or say running? From the perspective of the service control manager, it should say running. That might break other scenarios though, but i'm not sure - I think we can safely say the server is running when we try to log in and get a password failure. That was another part of the discussion. Right now we report any FATAL, so it might be a password problem, or something else, and it seems doing all FATALs is the best idea because it will catch any other cases like this. Is FATAL, in general, enough to conclude the server is running? No - specifically, we will send FATAL when the database system is starting up, which is exactly the one we want to *avoid*. I think we should only exclude the password case. I guess we could also do all fatal *except* list, but that seems more fragile. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Magnus Hagander mag...@hagander.net writes: On Wed, Nov 17, 2010 at 19:57, Bruce Momjian br...@momjian.us wrote: Is FATAL, in general, enough to conclude the server is running? No - specifically, we will send FATAL when the database system is starting up, which is exactly the one we want to *avoid*. I think we should only exclude the password case. I guess we could also do all fatal *except* list, but that seems more fragile. I believe that the above argument is exactly backwards. What we want here is to check the result of postmaster.c's canAcceptConnections(), and there are only a finite number of error codes that can result from rejections there. If we get past that, there are a large number of possible failures, but all of them indicate that the postmaster is in principle willing to accept connections. Checking for password errors only is utterly wrong: any other type of auth failure would be the same for this purpose, as would no such database, no such user, too many connections, etc etc etc. What we actually want here, and don't have, is the fabled pg_ping protocol... regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Tom Lane wrote: Magnus Hagander mag...@hagander.net writes: On Wed, Nov 17, 2010 at 19:57, Bruce Momjian br...@momjian.us wrote: Is FATAL, in general, enough to conclude the server is running? No - specifically, we will send FATAL when the database system is starting up, which is exactly the one we want to *avoid*. I think we should only exclude the password case. I guess we could also do all fatal *except* list, but that seems more fragile. I believe that the above argument is exactly backwards. What we want here is to check the result of postmaster.c's canAcceptConnections(), and there are only a finite number of error codes that can result from rejections there. If we get past that, there are a large number of possible failures, but all of them indicate that the postmaster is in principle willing to accept connections. Checking for password errors only is utterly wrong: any other type of auth failure would be the same for this purpose, as would no such database, no such user, too many connections, etc etc etc. Agreed. So how do we pass that info to libpq without exceeding the value of fixing this problem? Should we parse pg_controldata output? pg_upgrade could use machine-readable output from that too. What we actually want here, and don't have, is the fabled pg_ping protocol... Well, we are basically figuring how to implement that with this fix, whether it is part of pg_ctl or a separate binary. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian br...@momjian.us writes: Agreed. So how do we pass that info to libpq without exceeding the value of fixing this problem? Should we parse pg_controldata output? pg_upgrade could use machine-readable output from that too. pg_controldata seems 100% unrelated to this problem. You cannot even tell if the postmaster is alive just by inspecting pg_control. What we actually want here, and don't have, is the fabled pg_ping protocol... Well, we are basically figuring how to implement that with this fix, whether it is part of pg_ctl or a separate binary. Possibly the cleanest fix is to implement pg_ping as a libpq function. You do have to distinguish connection failures (ie connection refused) from errors that came back from the postmaster, and the easiest place to be doing that is inside libpq. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Tom Lane wrote: Bruce Momjian br...@momjian.us writes: Agreed. So how do we pass that info to libpq without exceeding the value of fixing this problem? Should we parse pg_controldata output? pg_upgrade could use machine-readable output from that too. pg_controldata seems 100% unrelated to this problem. You cannot even tell if the postmaster is alive just by inspecting pg_control. I was thinking of this: $ pg_controldata /u/pg/data ... Database cluster state: shut down What we actually want here, and don't have, is the fabled pg_ping protocol... Well, we are basically figuring how to implement that with this fix, whether it is part of pg_ctl or a separate binary. Possibly the cleanest fix is to implement pg_ping as a libpq function. You do have to distinguish connection failures (ie connection refused) from errors that came back from the postmaster, and the easiest place to be doing that is inside libpq. OK, so a new libpq function --- got it. Would we just pass the status from the backend or can it be done without backend modifications? -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian br...@momjian.us writes: Tom Lane wrote: Possibly the cleanest fix is to implement pg_ping as a libpq function. You do have to distinguish connection failures (ie connection refused) from errors that came back from the postmaster, and the easiest place to be doing that is inside libpq. OK, so a new libpq function --- got it. Would we just pass the status from the backend or can it be done without backend modifications? It would definitely be better to do it without backend mods, so that the functionality would work against back-branch postmasters. To my mind, the entire purpose of such a function is to classify the possible errors so that the caller doesn't have to. So I wouldn't consider that it ought to pass back the status from the backend. I think what we basically want is a function that takes a conninfo string (or one of the variants of that) and returns an enum defined more or less like this: * failed to connect to postmaster * connected, but postmaster is not accepting sessions * postmaster is up and accepting sessions I'm not sure those are exactly the categories we want, but something close to that. In particular, I don't know if there's any value in subdividing the not accepting sessions status --- pg_ctl doesn't really care, but other use-cases might want to tell the difference between the various canAcceptConnections failure states. BTW, it is annoying that we can't definitively distinguish postmaster is not running from a connectivity problem, but I can't see a way around that. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Tom Lane wrote: Bruce Momjian br...@momjian.us writes: Tom Lane wrote: Possibly the cleanest fix is to implement pg_ping as a libpq function. You do have to distinguish connection failures (ie connection refused) from errors that came back from the postmaster, and the easiest place to be doing that is inside libpq. OK, so a new libpq function --- got it. Would we just pass the status from the backend or can it be done without backend modifications? It would definitely be better to do it without backend mods, so that the functionality would work against back-branch postmasters. To my mind, the entire purpose of such a function is to classify the possible errors so that the caller doesn't have to. So I wouldn't consider that it ought to pass back the status from the backend. I think what we basically want is a function that takes a conninfo string (or one of the variants of that) and returns an enum defined more or less like this: * failed to connect to postmaster * connected, but postmaster is not accepting sessions * postmaster is up and accepting sessions I'm not sure those are exactly the categories we want, but something close to that. In particular, I don't know if there's any value in subdividing the not accepting sessions status --- pg_ctl doesn't really care, but other use-cases might want to tell the difference between the various canAcceptConnections failure states. BTW, it is annoying that we can't definitively distinguish postmaster is not running from a connectivity problem, but I can't see a way around that. Agreed. I will research this. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Nov 12, 2010 at 17:47, Bruce Momjian br...@momjian.us wrote: Tom Lane wrote: Bruce Momjian br...@momjian.us writes: Uh, I still cannot reproduce the failure: I would imagine you need -w option on the start. The whole issue here is whether start's wait-for-server-start code works. Thanks, I am now able to reproduce this. I was able to get this to report the .pgpass problem: $ psql postgres psql: FATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass $ pg_ctl stop waiting for server to shut down done server stopped $ pg_ctl -w -l /dev/null start waiting for server to startFATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass .FATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass .FATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass .^C I basically report the connection error string if it starts with FATAL:. I originally tried to check for an ERRCODE_INVALID_PASSWORD error field (see // comments), but it seems there is no way to access this, i.e. PQgetResult(conn) on a connection failure is always NULL. Anyway, perhaps FATAL is a better test because it will report any major failure, not just a .pgpass one. Patch attached. Bad Bruce, using C++ comments like that :P And non-context diff ;) Does this actually solve the *problem*, though? The problem is not what is reported on stdout/stderr, the problem is that the net result is that the server is reported as not started (by the service control manager) when it actually *is* started. In this case, stderr doesn't even go anywhere. What happens if you *don't* Ctrl-C it? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Magnus Hagander wrote: On Fri, Nov 12, 2010 at 03:49, Bruce Momjian br...@momjian.us wrote: Magnus Hagander wrote: On Fri, Sep 17, 2010 at 05:51, Ashesh Vashi ashesh.va...@enterprisedb.com wrote: Hi Mark, On of my college (Sujeet) has found a way to reproduce the same behaviour. 1. Installed PG 9.0 on Win XP SP3 2. Stop the Postgresql-9.0 service from service manager console 3. Create pgpass.conf in postgres (service account) user's profile with an incorrect password deliberately. (Refer: http://www.postgresql.org/docs/8.4/interactive/libpq-pgpass.html) 4. Now start the postgresql-9.0 service, it will return an error and the status ?? shows stopped 5. However i could connect to the psql shell and get the prompt which means ??? the server is running. I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Does anybody recall the specific reason for this? Do we need a way for pg_ctl to figure this out, or do we need to change it in PQconnecitonNeedsPassword()? I was not able to reproduce this failure on my BSD system using GIT head: ? ? ? ?$ psql test ? ? ? ?psql: FATAL: ?password authentication failed for user postgres ? ? ? ?password retrieved from file /u/postgres/.pgpass ? ? ? ?$ pg_ctl status ? ? ? ?pg_ctl: server is running (PID: 710) ? ? ? ?/usr/var/local/pgsql/bin/postgres -i The problem is not in pg_ctl status, it's in pg_ctl start. They're different codepaths - status never tries to actually connect, it just checks if the process is alive. Uh, I still cannot reproduce the failure: $ psql postgres psql: FATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass $ pg_ctl stop waiting for server to shut down done server stopped $ pg_ctl -l /dev/null start server starting (Got to love that new 9.0 pgpass error message.) -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Bruce Momjian br...@momjian.us writes: Uh, I still cannot reproduce the failure: I would imagine you need -w option on the start. The whole issue here is whether start's wait-for-server-start code works. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Tom Lane wrote:
Bruce Momjian br...@momjian.us writes:
Uh, I still cannot reproduce the failure:
I would imagine you need -w option on the start. The whole issue
here is whether start's wait-for-server-start code works.
Thanks, I am now able to reproduce this. I was able to get this to
report the .pgpass problem:
$ psql postgres
psql: FATAL: password authentication failed for user postgres
password retrieved from file /u/postgres/.pgpass
$ pg_ctl stop
waiting for server to shut down done
server stopped
$ pg_ctl -w -l /dev/null start
waiting for server to startFATAL: password authentication failed
for user postgres
password retrieved from file /u/postgres/.pgpass
.FATAL: password authentication failed for user postgres
password retrieved from file /u/postgres/.pgpass
.FATAL: password authentication failed for user postgres
password retrieved from file /u/postgres/.pgpass
.^C
I basically report the connection error string if it starts with FATAL:.
I originally tried to check for an ERRCODE_INVALID_PASSWORD error field
(see // comments), but it seems there is no way to access this, i.e.
PQgetResult(conn) on a connection failure is always NULL.
Anyway, perhaps FATAL is a better test because it will report any major
failure, not just a .pgpass one.
Patch attached.
--
Bruce Momjian br...@momjian.ushttp://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index 14d36b5..df71c16 100644
*** a/src/bin/pg_ctl/pg_ctl.c
--- b/src/bin/pg_ctl/pg_ctl.c
*** typedef enum
*** 70,75
--- 70,78
} CtlCommand;
#define DEFAULT_WAIT 60
+ //
+ ///* This is part of the protocol so just define it */
+ //#define ERRCODE_INVALID_PASSWORD 28P01
static bool do_wait = false;
static bool wait_set = false;
*** test_postmaster_connection(bool do_check
*** 511,516
--- 514,523
if ((conn = PQconnectdb(connstr)) != NULL
(PQstatus(conn) == CONNECTION_OK ||
PQconnectionNeedsPassword(conn)))
+ // /* only works with = 9.0 servers */
+ // (PQgetResult(conn)
+ // strcmp(PQresultErrorField(PQgetResult(conn), PG_DIAG_SQLSTATE),
+ // ERRCODE_INVALID_PASSWORD) == 0)))
{
PQfinish(conn);
success = true;
*** test_postmaster_connection(bool do_check
*** 518,523
--- 525,533
}
else
{
+ /* report fatal errors like invalid .pgpass passwords */
+ if (strncmp(PQerrorMessage(conn), FATAL:, strlen(FATAL:)) == 0)
+ fputs(PQerrorMessage(conn), stderr);
PQfinish(conn);
#if defined(WIN32)
--
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Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Magnus Hagander wrote: On Fri, Sep 17, 2010 at 05:51, Ashesh Vashi ashesh.va...@enterprisedb.com wrote: Hi Mark, On of my college (Sujeet) has found a way to reproduce the same behaviour. 1. Installed PG 9.0 on Win XP SP3 2. Stop the Postgresql-9.0 service from service manager console 3. Create pgpass.conf in postgres (service account) user's profile with an incorrect password deliberately. (Refer: http://www.postgresql.org/docs/8.4/interactive/libpq-pgpass.html) 4. Now start the postgresql-9.0 service, it will return an error and the status ?? shows stopped 5. However i could connect to the psql shell and get the prompt which means ??? the server is running. I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Does anybody recall the specific reason for this? Do we need a way for pg_ctl to figure this out, or do we need to change it in PQconnecitonNeedsPassword()? I was not able to reproduce this failure on my BSD system using GIT head: $ psql test psql: FATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass $ pg_ctl status pg_ctl: server is running (PID: 710) /usr/var/local/pgsql/bin/postgres -i -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Nov 12, 2010 at 03:49, Bruce Momjian br...@momjian.us wrote: Magnus Hagander wrote: On Fri, Sep 17, 2010 at 05:51, Ashesh Vashi ashesh.va...@enterprisedb.com wrote: Hi Mark, On of my college (Sujeet) has found a way to reproduce the same behaviour. 1. Installed PG 9.0 on Win XP SP3 2. Stop the Postgresql-9.0 service from service manager console 3. Create pgpass.conf in postgres (service account) user's profile with an incorrect password deliberately. (Refer: http://www.postgresql.org/docs/8.4/interactive/libpq-pgpass.html) 4. Now start the postgresql-9.0 service, it will return an error and the status ?? shows stopped 5. However i could connect to the psql shell and get the prompt which means ??? the server is running. I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Does anybody recall the specific reason for this? Do we need a way for pg_ctl to figure this out, or do we need to change it in PQconnecitonNeedsPassword()? I was not able to reproduce this failure on my BSD system using GIT head: $ psql test psql: FATAL: password authentication failed for user postgres password retrieved from file /u/postgres/.pgpass $ pg_ctl status pg_ctl: server is running (PID: 710) /usr/var/local/pgsql/bin/postgres -i The problem is not in pg_ctl status, it's in pg_ctl start. They're different codepaths - status never tries to actually connect, it just checks if the process is alive. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Sep 17, 2010 at 05:51, Ashesh Vashi ashesh.va...@enterprisedb.com wrote: Hi Mark, On of my college (Sujeet) has found a way to reproduce the same behaviour. 1. Installed PG 9.0 on Win XP SP3 2. Stop the Postgresql-9.0 service from service manager console 3. Create pgpass.conf in postgres (service account) user's profile with an incorrect password deliberately. (Refer: http://www.postgresql.org/docs/8.4/interactive/libpq-pgpass.html) 4. Now start the postgresql-9.0 service, it will return an error and the status shows stopped 5. However i could connect to the psql shell and get the prompt which means the server is running. I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Does anybody recall the specific reason for this? Do we need a way for pg_ctl to figure this out, or do we need to change it in PQconnecitonNeedsPassword()? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Magnus Hagander mag...@hagander.net writes: I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Why should it? That code is complicated enough, I don't think it needs to have a behavior of pretending that a wrong entry isn't there. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Sep 24, 2010 at 16:04, Tom Lane t...@sss.pgh.pa.us wrote: Magnus Hagander mag...@hagander.net writes: I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Why should it? That code is complicated enough, I don't think it needs to have a behavior of pretending that a wrong entry isn't there. In that case, we should probably teach pg_ctl about this case, no? Since it clearly gives an incorrect message to the user now... -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On 09/24/2010 10:15 AM, Magnus Hagander wrote: On Fri, Sep 24, 2010 at 16:04, Tom Lanet...@sss.pgh.pa.us wrote: Magnus Hagandermag...@hagander.net writes: I took a quick look at the code, and from what I can tell this is because PQconnectionNeedsPassword() always returns false if a pgpass.conf has been used. There is no handling the case where pgpass is used, but has an incorrect password. Why should it? That code is complicated enough, I don't think it needs to have a behavior of pretending that a wrong entry isn't there. In that case, we should probably teach pg_ctl about this case, no? Since it clearly gives an incorrect message to the user now... pg_ctl decides that the server is running iff it can connect to it. Do you intend to provide for a different test? Setting an incorrect password for the service account sounds like pilot error to me. cheers andrew -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Andrew Dunstan and...@dunslane.net writes: On 09/24/2010 10:15 AM, Magnus Hagander wrote: In that case, we should probably teach pg_ctl about this case, no? Since it clearly gives an incorrect message to the user now... pg_ctl decides that the server is running iff it can connect to it. Do you intend to provide for a different test? Seems like getting a password challenge from the server is sufficient evidence that the server is running, whether we are able to meet the challenge or not. Perhaps we could just twiddle pg_ctl's is it up test a bit to notice whether the connect failure was of this sort. (Of course, a pg_ping utility would be a better answer, but nobody's gotten around to that in more than ten years, so I'm not holding my breath.) regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On Fri, Sep 24, 2010 at 4:11 PM, Tom Lane t...@sss.pgh.pa.us wrote: (Of course, a pg_ping utility would be a better answer, but nobody's gotten around to that in more than ten years, so I'm not holding my breath.) Hmm, that sounded like it could be my 9.1 mini project - then Google showed me that SeanC wrote something already. http://archives.postgresql.org/pgsql-patches/2003-07/msg00053.php -- Dave Page Blog: http://pgsnake.blogspot.com Twitter: @pgsnake EnterpriseDB UK: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
Dave Page dp...@pgadmin.org writes: On Fri, Sep 24, 2010 at 4:11 PM, Tom Lane t...@sss.pgh.pa.us wrote: (Of course, a pg_ping utility would be a better answer, but nobody's gotten around to that in more than ten years, so I'm not holding my breath.) Hmm, that sounded like it could be my 9.1 mini project - then Google showed me that SeanC wrote something already. http://archives.postgresql.org/pgsql-patches/2003-07/msg00053.php Huh, I wonder why we never adopted that? Although I'd be inclined to do most of the heavy lifting inside libpq, myself, and this is way more verbose than what pg_ctl wants. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #5650: Postgres service showing as stopped when in fact it is running
On 09/24/2010 11:11 AM, Tom Lane wrote: Andrew Dunstanand...@dunslane.net writes: On 09/24/2010 10:15 AM, Magnus Hagander wrote: In that case, we should probably teach pg_ctl about this case, no? Since it clearly gives an incorrect message to the user now... pg_ctl decides that the server is running iff it can connect to it. Do you intend to provide for a different test? Seems like getting a password challenge from the server is sufficient evidence that the server is running, whether we are able to meet the challenge or not. Perhaps we could just twiddle pg_ctl's is it up test a bit to notice whether the connect failure was of this sort. pg_ctl does in fact use that sort of logic: if ((conn = PQconnectdb(connstr)) != NULL (PQstatus(conn) == CONNECTION_OK || PQconnectionNeedsPassword(conn))) But of course, libpq won't set that last condition if there is a bad password in the pgpass file, which seems a rather perverse thing to do. cheers andrew
