openldap-bugs September 2023

openldap-bugs@openldap.org

1 participants
145 discussions

[Issue 9619] New: mdb_env_copy2 with MDB_CP_COMPACT in mdb.master3 produces corrupt mdb file
by openldap-its＠openldap.org 29 Apr '26

29 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9619 Issue ID: 9619 Summary: mdb_env_copy2 with MDB_CP_COMPACT in mdb.master3 produces corrupt mdb file Product: LMDB Version: 0.9.29 Hardware: All OS: Windows Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: kriszyp(a)gmail.com Target Milestone: --- When copying an LMDB database with mdb_env_copy2 with the MDB_CP_COMPACT with mdb.master3, the resulting mdb file seems to be corrupt and when using it in LMDB, I get segmentation faults. Copying without the compacting flag seems to work fine. I apologize, I know this is not a very good issue report, as I haven't had a chance to actually narrow this down to a more reproducible/isolated case, or look for how to patch. I thought I would report in case there are any ideas on what could cause this. The segmentation faults always seem to be memory write faults (as opposed to try fault on trying to read). Or perhaps the current backup/copying functionality is eventually going to be replaced by incremental backup/copying anyway (https://twitter.com/hyc_symas/status/1315651814096875520). I'll try to update this if I get a chance to investigate more, but otherwise feel free to ignore/consider low-priority since the work around is easy. -- You are receiving this mail because: You are on the CC list for the issue.

1 10

[Issue 9769] New: Patch new feature batch get
by openldap-its＠openldap.org 28 Apr '26

28 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9769 Issue ID: 9769 Summary: Patch new feature batch get Product: LMDB Version: unspecified Hardware: All OS: All Status: UNCONFIRMED Keywords: needs_review Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: rouzier(a)gmail.com Target Milestone: --- Created attachment 859 --> https://bugs.openldap.org/attachment.cgi?id=859&action=edit New functionality mdb_cursor_get_batch New functionality mdb_cursor_get_batch mdb_cursor_get_batch retrieves a page worth of key/values. This is to reduce the number of function calls when doing a scan of the database. -- You are receiving this mail because: You are on the CC list for the issue.

1 9

[Issue 9291] New: Detection of corrupted database files
by openldap-its＠openldap.org 27 Apr '26

27 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9291 Issue ID: 9291 Summary: Detection of corrupted database files Product: LMDB Version: unspecified Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: markus(a)objectbox.io Target Milestone: --- Let's assume we have to deal with a corrupted database for whatever reason (e.g. broken hardware or file system). Current behavior seems to be mostly undefined, which is understandable as it's not known what is broken (e.g. there are no checksums). For example, I'm seeing a SIGBUS in mdb_page_touch because the cursor's top page (mp) is pointing to invalid memory (0x7f99cf004000) during a commit: mdb_page_touch mdb.c:2772 mdb_page_search mdb.c:6595 mdb_freelist_save mdb.c:3575 mdb_txn_commit mdb.c:4060 Cursor data at that point: mc_snum = 1, mc_top = 0; myki[0] = 0 A SIGBUS is troublesome as it crashes the process, and I wonder if there are other ways to detect such inconsistencies. If that be possible there could be user-specific handling in place. E.g. a user might start a new database file. This issue was reported by our users, which also provided DB files: https://github.com/objectbox/objectbox-java/issues/859 I did not find a lot of consistency checks besides MDB_PAGE_NOTFOUND and MDB_CORRUPTED. Also, I think there's no current way to thoroughly check a DB file (e.g. like fsck for the DB file)? My first idea other than checksums was to walk through the branch pages from the root and check if the referenced pages are within reasonable bounds. Also check the page content (e.g. nodes, flags). Additionally (optionally?), it should be possible to check that the key values are actually sorted. So, it boils down to 3 points in summary: 1.) If there no way to check the DB file for consistency yet(?), which approach do you think would make sense? There might be two modes; one for a through check through all data, and a quick check that does not take long and could be e.g. done when opening the DB. Goal is to avoid process crashes and let users handle the situation. 2.) In general, is it possible to add more consistency checks in regular DB operations? 3.) Could the the particular situation (for which I provided the stack trace) detected (e.g. is myki[0] = 0 legal here?) I'd be happy to provide a patch if you provide some direction where you want to take that. -- You are receiving this mail because: You are on the CC list for the issue.

1 26

[Issue 9388] New: mdb_stat for DupSort DBI shows incorrect data
by openldap-its＠openldap.org 27 Apr '26

27 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9388 Issue ID: 9388 Summary: mdb_stat for DupSort DBI shows incorrect data Product: LMDB Version: 0.9.26 Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: AskAlexSharov(a)gmail.com Target Milestone: --- It doesn't include pages pages used for values. -- You are receiving this mail because: You are on the CC list for the issue.

1 2

[Issue 9360] New: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid
by openldap-its＠openldap.org 26 Apr '26

26 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9360 Issue ID: 9360 Summary: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid Product: LMDB Version: unspecified Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: spam(a)markandruth.co.uk Target Milestone: --- I have 2 python scripts writing to a database (lmdb 0.9.26, py-lmdb 0.98) and 5-10 lua processes (with lightningmdb module which uses lmdb 0.9.22) which are long-running serving queries from the database. The database seems fine, not corrupted, and the python writes still working all the time. But periodically (perhaps 10-20% of the time), in a way I am unable to reliably reproduce, when the lua starts up every time a query is issued txn dbi_open returns "MDB_BAD_TXN: Transaction must abort, has a child, or is invalid". A direct restart of the processes does not fix this issue, however stopping lua+python and then starting again after a 5-20s wait usually fixes the issue. This has been reproduced over multiple servers but I'm at a loss as to how to debug this any further? -- You are receiving this mail because: You are on the CC list for the issue.

1 7

[Bug 9208] New: LMDB feature request: variant of mdb_env_copy{,fd2} that takes transaction as parameter
by openldap-its＠openldap.org 24 Apr '26

24 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9208 Bug ID: 9208 Summary: LMDB feature request: variant of mdb_env_copy{,fd2} that takes transaction as parameter Product: LMDB Version: unspecified Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: github(a)nicwatson.org Target Milestone: --- The mdb_env_copy* functions create a read transaction themselves to run the backup on. New variants of these functions (one for mdb_env_copy2 and one for mdb_env_copyfd2) would have a transaction parameter. This transaction would be used instead of creating a new transaction. Application code could use these new functions to synchronize consistent live backups across multiple LMDB instances (potentially across multiple hosts). -- You are receiving this mail because: You are on the CC list for the bug.

1 1

[Issue 10034] New: Assertion 'i < NUMKEYS(mp)' failed in mdb_page_search_root()"
by openldap-its＠openldap.org 23 Apr '26

23 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=10034 Issue ID: 10034 Summary: Assertion 'i < NUMKEYS(mp)' failed in mdb_page_search_root()" Product: LMDB Version: 0.9.23 Hardware: Other OS: Linux Status: UNCONFIRMED Keywords: needs_review Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: 763280032(a)qq.com Target Milestone: --- We found that when lmdb is opened after OS startup and data is written to it, lmdb will trigger abort probabilistically(Restart the OS 600 times will trigger once); We want to know what situation triggers this issue(Assertion 'i < NUMKEYS(mp)' failed in mdb_page_search_root()); we want to know if there is a problem with our usage; Please Help Us (gdb) x/8s 0x8baee988 0x8baee988: "8\373Բ\b\371Բmdb.c:5542: Assertion 'i < NUMKEYS(mp)' failed in mdb_page_search_root()" -- You are receiving this mail because: You are on the CC list for the issue.

1 2

[Issue 9475] New: Add support for MAP_POPULATE
by openldap-its＠openldap.org 22 Apr '26

22 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9475 Issue ID: 9475 Summary: Add support for MAP_POPULATE Product: LMDB Version: unspecified Hardware: All OS: Linux Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: aa531811820(a)gmail.com Target Milestone: --- In some case (such as cloud computing platforms), the reading speed of large files is very fast while the small files is very slow, and we have enough memory, so we hope to prefetch the entire LMDB file into the memory during MMAP through the MAP_POPULATE flag . According to our test, this is faster than using readahead flag. Here are some test data: # mmap with no readahead read one sample: 0.2s total time: 4800s # mmap with readahead read one sample: 0.0001s~0.03s total time: 95.86s # mmap with MAP_POPULATE db init: 20s read one sample: 0.0001s total time: 78s -- You are receiving this mail because: You are on the CC list for the issue.

1 4

[Issue 9539] New: ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(env, 0)
by openldap-its＠openldap.org 22 Apr '26

22 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9539 Issue ID: 9539 Summary: ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(env, 0) Product: LMDB Version: 0.9.28 Hardware: x86_64 OS: Windows Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: igfoo(a)github.com Target Milestone: --- On Windows, with the attached program and the commands below, I am getting ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(env, 0) on the latest 0.9.28 release. The program works as expected on mdb.master. git clone https://github.com/LMDB/lmdb.git cd lmdb git reset --hard LMDB_0.9.28 cd .. call "c:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat" cl -Femain.exe -Ilmdb/libraries/liblmdb main.c lmdb/libraries/liblmdb/mdb.c lmdb/libraries/liblmdb/midl.c Advapi32.lib cl -Feloop.exe -Ilmdb/libraries/liblmdb loop.c lmdb/libraries/liblmdb/mdb.c lmdb/libraries/liblmdb/midl.c Advapi32.lib .\main.exe Example output: Loop 300000 400000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 500000 600000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 200000 300000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 400000 500000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 600000 700000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 100000 200000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 700000 800000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 900000 1000000 starting. Got ERROR_USER_MAPPED_FILE from mdb_env_set_mapsize(0). Loop 800000 900000 starting. Loop 800000 900000 done. Non-zero 0 exit code 1. Non-zero 1 exit code 1. Non-zero 2 exit code 1. Non-zero 3 exit code 1. Non-zero 4 exit code 1. Non-zero 5 exit code 1. Non-zero 6 exit code 1. Non-zero 8 exit code 1. All done. -- You are receiving this mail because: You are on the CC list for the issue.

1 5

[Issue 9397] New: LMDB: A second process opening a file with MDB_WRITEMAP can cause the first to SIGBUS
by openldap-its＠openldap.org 22 Apr '26

22 Apr '26

https://bugs.openldap.org/show_bug.cgi?id=9397 Issue ID: 9397 Summary: LMDB: A second process opening a file with MDB_WRITEMAP can cause the first to SIGBUS Product: LMDB Version: 0.9.26 Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs(a)openldap.org Reporter: github(a)nicwatson.org Target Milestone: --- Created attachment 780 --> https://bugs.openldap.org/attachment.cgi?id=780&action=edit Full reproduction of SIGBUS MDB_WRITEMAP issue (works on Linux only) The fundamental problem is that a ftruncate() on Linux that makes a file smaller will cause accesses past the new end of the file to SIGBUS (see the mmap man page). The sequence that causes a SIGBUS involves two processes. 1. The first process opens a new LMDB file with MDB_WRITEMAP. 2. The second process opens the same LMDB file with MDB_WRITEMAP and with an explicit map_size smaller than the first process's map size. * This causes an ftruncate that makes the underlying file *smaller*. 3. (Optional) The second process closes the environment and exits. 4. The first process opens a write transaction and writes a bunch of data. 5. The first process commits the transaction. This causes a memory read from the mapped memory that's now past the end of the file. On Linux, this triggers a SIGBUS. Attached is code that fully reproduces the problem on Linux. The most straightforward solution is to allow ftruncate to *reduce* the file size if it is the only reader. Another possibility is check the file size and ftruncate if necessary every time a write transaction is opened. A third possibility is to catch the SIGBUS signal. Repro note: I used clone() to create the subprocess to most straightforwardly demonstrate that the problem is not due to inherited file descriptors. The problem still manifests when the processes are completely independent. -- You are receiving this mail because: You are on the CC list for the issue.

1 11

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

openldap-bugs September 2023