Hi all, I'm using questdb 6.5.5, while the questdb always crashed and reported insufficient memory, after increasing memory from 64G to 128G, the issue still exist. For details, please see the below log and attachments, thanks in advanced.

Unsafe.malloc() OutOfMemoryError, mem_used=12333387838, size=33554432, memoryTag=10Unsafe.malloc() OutOfMemoryError, mem_used=12337601350, size=33554432, memoryTag=10Unsafe.malloc() OutOfMemoryError, mem_used=12417353582, size=33554432, memoryTag=10Unsafe.malloc() OutOfMemoryError, mem_used=12346032502, size=33554432, memoryTag=10Unsafe.malloc() OutOfMemoryError, mem_used=12388013182, size=33554432, memoryTag=10OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00007f0623c80000, 262144, 0) failed; error='Not enough space' (errno=12)

2022-12-22T06:29:17.531090Z I i.q.c.TableReader open partition /data/questdb/db/pgdb_aps.xxaps.ocp_req_bill_history/2022-10-15T01.94 [rowCount=16828, partitionNameTxn=94, transientRowCount=65731, partitionIndex=671, partitionCount=894]^M
2022-12-22T06:29:17.532167Z C i.q.c.p.PGConnectionContext error [msg=`could not mmap  [size=134632, offset=0, fd=65255, memUsed=12342479714, fileLen=134632]`, errno=`12]^M
[80.912s][warning][os,thread] Attempt to deallocate stack guard pages failed (0x00007fbb1cbe3000-0x00007fbb1cbe7000).
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 65536 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /data/questdb//db/hs_err_pid+2621.log
2022-12-22T06:29:36.790959Z I pg-server connected [ip=10.21.46.31, fd=65255]^M
2022-12-22T06:29:36.792770Z I pg-server connected [ip=10.21.46.31, fd=65256]^M
2022-12-22T06:29:36.793809Z I i.q.c.p.PGConnectionContext protocol [major=3, minor=0]^M
2022-12-22T06:29:36.793843Z I i.q.c.p.PGConnectionContext property [name=user, value=admin]^M
2022-12-22T06:29:36.793852Z I i.q.c.p.PGConnectionContext property [name=database, value=qdb]^M
2022-12-22T06:29:36.793858Z I i.q.c.p.PGConnectionContext property [name=client_encoding, value=UTF8]^M
2022-12-22T06:29:36.793864Z I i.q.c.p.PGConnectionContext property [name=DateStyle, value=ISO]^M
2022-12-22T06:29:36.793870Z I i.q.c.p.PGConnectionContext property [name=TimeZone, value=Asia/Shanghai]^M
2022-12-22T06:29:36.793876Z I i.q.c.p.PGConnectionContext property [name=extra_float_digits, value=2]^M
2022-12-22T06:29:36.793998Z I i.q.c.p.PGConnectionContext protocol [major=3, minor=0]^M
2022-12-22T06:29:36.794010Z I i.q.c.p.PGConnectionContext property [name=user, value=admin]^M
2022-12-22T06:29:36.794017Z I i.q.c.p.PGConnectionContext property [name=database, value=qdb]^M
2022-12-22T06:29:36.794022Z I i.q.c.p.PGConnectionContext property [name=client_encoding, value=UTF8]^M
2022-12-22T06:29:36.794028Z I i.q.c.p.PGConnectionContext property [name=DateStyle, value=ISO]^M
2022-12-22T06:29:36.794034Z I i.q.c.p.PGConnectionContext property [name=TimeZone, value=Asia/Shanghai]^M
2022-12-22T06:29:36.794040Z I i.q.c.p.PGConnectionContext property [name=extra_float_digits, value=2]^M
2022-12-22T06:29:36.794605Z I i.q.c.p.PGConnectionContext parse [fd=65255, q=SET extra_float_digits = 3]^M
2022-12-22T06:29:36.794975Z I i.q.c.p.PGConnectionContext parse [fd=65256, q=SET extra_float_digits = 3]^M
2022-12-22T06:29:36.795165Z I i.q.c.p.PGConnectionContext parse [fd=65255, q=SET application_name = 'PostgreSQL JDBC Driver']^M

Hi Jun, You need to increase the kernel limits: https://questdb.io/docs/operations/capacity-planning/#maximum-open-files https://questdb.io/docs/operations/capacity-planning/#max-virtual-memory-areas-limit

Would it also be possible to upgrade to 6.6.1?, newer releases bring bug fixes and improvements https://github.com/questdb/questdb/releases/tag/6.6.1