5:22 a.m.
Hi,
I am using lmdb to implement a graph db via java JNI.
Initial results are amazing.
Anyhow I am having trouble with deletions.
I am getting MDB_PAGE_FULL when trying to delete.
A simplified version of the code is as follows.
//set the key
...
while ((rc = mdb_cursor_get(vertexCursor, &key, &data,
MDB_SET_RANGE)) == 0) {
rc = mdb_cursor_del(vertexCursor, 0);
if (rc != 0) {
printf("removeVertex 4 %i\n", rc);
goto fail;
}
//set the key
...
}
The mdb_cursor_del returns a error code -30786 (MDB_PAGE_FULL) on about
the 38th loop.
if there are very few entries then the exception does not happen.
Is there something obvious that I am doing wrong to cause a
MDB_PAGE_FULL exception?
Thanks
Pieter
5:55 a.m.
New subject: MDB_PAGE_FULL
Pieter Martin wrote:
Hi,
I am using lmdb to implement a graph db via java JNI.
Initial results are amazing.
Anyhow I am having trouble with deletions.
I am getting MDB_PAGE_FULL when trying to delete.
Sounds like ITS#7756, you should try with git rev
b77689f97572980d5de729e2fe6d8a5e6e9d6218
A simplified version of the code is as follows.
//set the key
...
while ((rc = mdb_cursor_get(vertexCursor, &key, &data,
MDB_SET_RANGE)) == 0) {
rc = mdb_cursor_del(vertexCursor, 0);
if (rc != 0) {
printf("removeVertex 4 %i\n", rc);
goto fail;
}
//set the key
...
}
The mdb_cursor_del returns a error code -30786 (MDB_PAGE_FULL) on about
the 38th loop.
if there are very few entries then the exception does not happen.
Is there something obvious that I am doing wrong to cause a
MDB_PAGE_FULL exception?
Thanks
Pieter
--
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/
2:50 a.m.
New subject: MDB_PAGE_FULL
Hi,
I was already on that revision.
The problems goes away by using mdb_del instead. However I am still
getting strange behaviour. In particular on deletion. It seems as though
the cursor gets confused when the data it refers to has been removed.
Unfortunately I am unable to reproduce the error in a simple scenario.
It is happening from java code calling lmdb via JNI.
In general I keep a cursor open on the db. Then I remove an entry and
after that call MDB_NEXT on the cursor. Occasionally it then crashes.
I noticed that before it crashes it enters the following code in
mdb_cursor_next
static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data,
MDB_cursor_op op) {
...
skip:
...
(line 5098) if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(mc, leaf); //this crashes
}
...
}
Trying to duplicate the error from c I can not get that code to execute.
Any pointers as to what I might be doing incorrect?
When removing data, can MDB_NEXT be called or should the cursor be reset
first?
Thanks
Pieter
On 23/12/2013 15:55, Howard Chu wrote:
Pieter Martin wrote:
> Hi,
>
> I am using lmdb to implement a graph db via java JNI.
> Initial results are amazing.
>
> Anyhow I am having trouble with deletions.
>
> I am getting MDB_PAGE_FULL when trying to delete.
Sounds like ITS#7756, you should try with git rev
b77689f97572980d5de729e2fe6d8a5e6e9d6218
>
> A simplified version of the code is as follows.
>
>
> //set the key
> ...
>
> while ((rc = mdb_cursor_get(vertexCursor, &key, &data,
> MDB_SET_RANGE)) == 0) {
>
> rc = mdb_cursor_del(vertexCursor, 0);
> if (rc != 0) {
> printf("removeVertex 4 %i\n", rc);
> goto fail;
> }
>
> //set the key
> ...
> }
>
> The mdb_cursor_del returns a error code -30786 (MDB_PAGE_FULL) on about
> the 38th loop.
>
> if there are very few entries then the exception does not happen.
> Is there something obvious that I am doing wrong to cause a
> MDB_PAGE_FULL exception?
>
> Thanks
> Pieter
>
>
>
7:26 a.m.
New subject: MDB_PAGE_FULL
On 2014-01-02 11:50, Pieter Martin wrote:
The problems goes away by using mdb_del instead. However I am still
getting strange behaviour. In particular on deletion. It seems as
though the cursor gets confused when the data it refers to has been
removed.
There are DUPSORT-cursor bugs when you have a cursor on a DBI and
modify it using another cursor. ITS#7771 in www.openldap.org/its/,
not yet fixed. Is that what you are doing?
Unfortunately I am unable to reproduce the error in a simple
scenario. It is happening from java code calling lmdb via JNI.
In general I keep a cursor open on the db. Then I remove an entry and
after that call MDB_NEXT on the cursor. Occasionally it then crashes.
(...)
When removing data, can MDB_NEXT be called or should the cursor be
reset first?
It should work, but that code is fairly new.
--
Hallvard
3423
days inactive
3450
days old
openldap-technical@openldap.org
3 comments
3 participants
participants (3)
-
Hallvard Breien Furuseth -
Howard Chu -
Pieter Martin