Hi, Yes, with version 1.3.162 and older, the following problem can occur: on out of disk space, the database can get corrupt sometimes, if later write operations succeed. The same problem happens on other kinds of I/O exceptions (where one or some of the writes fail, but subsequent writes succeed). Now the file is closed on the first unsuccessful write operation, so that later requests fail consistently.
With version 1.3.171 and older: when using local temporary tables and not dropping them manually before closing the session, and then killing the process could result in a database that couldn't be opened. I think it could be either one of those problems. Database corruptions are really annoying, but unfortunately it is quite hard to ensure such problems can never occur. H2 currently uses quite a "traditional" database file format (b-tree pages of a fixed size, overflow pages, transaction log, undo log). The file format and transaction log / recovery logic are quite complex. Still there are corruptions sometimes... This is one of the reasons to change to a different, much simpler storage format (the MVStore) in the future. Of course there is still a risk, but my hope is that the risk is much lower, because the algorithm is simpler. Regards, Thomas On Tue, Dec 17, 2013 at 8:06 PM, Geren White <[email protected]> wrote: > Also, some additional information. The corrupted database error only > happened on a certain query. Here is the error and query: > > > *Message: File corrupted while reading record: "[2587] stream data key:781 > pos:11 remaining:0". Possible solution: use the recovery tool; SQL > statement:* > > *SELECT * FROM MRKMAGDTA.FLDSPF80 WHERE (FLFMNM = 'SHLBL70' AND FLDMOD = > 'ZTZ170XI3') OR (FLFMNM = 'WMOSLBL' AND FLDMOD = '*MASTER') [90030-162]* > I connected to the h2 database through H2 console and received the same > error if I ran that query. If I removed the OR portion the query would run. > > On Tuesday, December 17, 2013 12:15:38 PM UTC-5, Geren White wrote: >> >> Hello, >> I have an application that uses the H2 database and one of our >> customers had an issue with a corrupted database the other day. We run the >> tcp database server with allow others option set. On the customers >> environment we have two of our applications running, so two of the H2 >> database servers are running. They are configured to run on separate ports >> and handle connections to different databases. >> >> Our connection string is: jdbc:h2:tcp://localhost:PORT/ >> H2_DIR/H2_DB;MODE=MYSQL >> The port, h2_dir, and h2_db get filled in with valid values. From >> looking over other database corruption issues I don't believe we are using >> any dangerous options. I haven't seen anything against using the MYSQL >> option. >> We also have client applications that will connect in the same manner but >> obviously with the IP address instead of localhost. >> >> I was able to recover the h2 database using the recovery tool. Looking >> over the transaction log I do see one error but I'm unsure of what it >> means. I've attached the transaction log if someone else could take a look >> that would be greatly appreciated. The error that I noticed occurred on >> line 13682. >> I also have the corrupted database if any one would like to take a look >> at that. >> I'm pretty sure the database was created with version 1.3.162. I >> recovered it with version 1.3.173. >> >> From what I've seen there are two major corruption issues. If the server >> ran out of disk space and we attempted to write to the database. Also if >> there are temporary tables and the application was shut down unexpectedly. >> The server that was running the database has plenty of space. Also we're >> not using any temporary tables and the customer said that the application >> had been running for about a month with no shutdowns. So I don't think >> either of these could be the issue. >> >> Thank you, >> Geren White >> >> >> -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/h2-database. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/h2-database. For more options, visit https://groups.google.com/groups/opt_out.
