Une application Java 11 se bloque d'une manière qui, d'après ce que j'ai compris, est impossible avec les paramètres que j'ai.
L'application en question fonctionne sur Amazon Linux 2 et utilise Java 11. Le serveur est un cloud EC2 avec 4 Go de mémoire vive. Le serveur n'a pas d'espace d'échange.
Ce serveur est purement dédié à cette application, il ne doit rien y avoir d'autre que l'application, les choses requises par l'application (comme ngnix), et les choses qui surveillent l'application.
En outre, l'application démarre avec les arguments Xmx et Xms définis à la même valeur : 2136M, de sorte que la JVM ne devrait pas demander de mémoire au système d'exploitation, sauf au moment du démarrage.
L'application a tendance à utiliser environ 250 Mo de mémoire sous des charges standard, et environ 400-500 Mo sous des charges "inhabituellement élevées". Cela inclut les frais généraux du conteneur de servlets et autres. L'affectation de plus de 2 gigas de mémoire est destinée à fournir un petit tampon en cas de tentative de DDOS.
L'application se bloque après avoir fonctionné pendant un certain temps, généralement au moins 24 heures.
D'après ce que j'ai compris, ce type de plantage devrait être impossible, étant donné que Xmx et Xms sont réglés de la même manière, de sorte que la JVM ne devrait pas demander plus de mémoire au système d'exploitation une fois qu'elle a démarré.
Voici quelques extraits du fichier err_pid_####.log
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 65536 bytes for committing reserved memory.
# Possible reasons:
# The system is out of physical RAM or swap space
# The process is running with CompressedOops enabled, and the Java Heap may be blocking the growth of the native heap
# Possible solutions:
# Reduce memory load on the system
# Increase physical memory or swap space
# Check if swap backing store is full
# Decrease Java heap size (-Xmx/-Xms)
# Decrease number of Java threads
# Decrease Java thread stack sizes (-Xss)
# Set larger code cache with -XX:ReservedCodeCacheSize=
# JVM is running with Zero Based Compressed Oops mode in which the Java heap is
# placed in the first 32GB address space. The Java Heap base address is the
# maximum limit for the native heap growth. Please use -XX:HeapBaseMinAddress
# to set the Java Heap base and to place the Java Heap above 32GB virtual address.
# This output file may be truncated or incomplete.
#
# Out of Memory Error (os_linux.cpp:2709), pid=2100, tid=2113
#
# JRE version: OpenJDK Runtime Environment (11.0+28) (build 11+28)
# Java VM: OpenJDK 64-Bit Server VM (11+28, mixed mode, tiered, compressed oops, g1 gc, linux-amd64)
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
--------------- S U M M A R Y ------------
Command Line: -Xmx2136M -Xms2136M -javaagent:/opt/jetty/newrelic/newrelic.jar -Djetty.home=/opt/jetty -Djetty.base=/opt/jetty-base -Djava.io.tmpdir=/tmp /opt/jetty/start.jar jetty.state=/opt/jetty-base/jetty.state jetty-started.xml start-log-file=/{REDACTED}.log
Host: Intel(R) Xeon(R) Platinum 8175M CPU @ 2.50GHz, 2 cores, 3G, Amazon Linux release 2 (Karoo)
Time: Tue Apr 9 16:22:38 2019 UTC elapsed time: 132340 seconds (1d 12h 45m 40s)
--------------- T H R E A D ---------------
Current thread (0x00007f6f4884c800): JavaThread "C2 CompilerThread0" daemon [_thread_in_vm, id=2113, stack(0x00007f6f01330000,0x00007f6f01431000)]
Current CompileTask:
C2:132341001 41817 4 com.newrelic.agent.deps.org.apache.http.impl.client.HttpClientBuilder::build (1754 bytes)
--------------- S Y S T E M ---------------
OS:Amazon Linux release 2 (Karoo)
uname:Linux 4.14.104-95.84.amzn2.x86_64 #1 SMP Sat Mar 2 00:40:20 UTC 2019 x86_64
libc:glibc 2.26 NPTL 2.26
rlimit: STACK 8192k, CORE 0k, NPROC 4096, NOFILE 4096, AS infinity, DATA infinity, FSIZE infinity
load average:0.00 0.03 0.00
/proc/meminfo:
MemTotal: 3978224 kB
MemFree: 103460 kB
MemAvailable: 0 kB
Buffers: 0 kB
Cached: 3744 kB
SwapCached: 0 kB
Active: 3795996 kB
Inactive: 2028 kB
Active(anon): 3794792 kB
Inactive(anon): 224 kB
Active(file): 1204 kB
Inactive(file): 1804 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 36 kB
Writeback: 0 kB
AnonPages: 3794564 kB
Mapped: 2504 kB
Shmem: 452 kB
Slab: 32256 kB
SReclaimable: 13572 kB
SUnreclaim: 18684 kB
KernelStack: 3104 kB
PageTables: 12828 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 1989112 kB
Committed_AS: 2910992 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
AnonHugePages: 0 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 126952 kB
DirectMap2M: 4005888 kB
DirectMap1G: 0 kB
/proc/sys/kernel/threads-max (system-wide limit on the number of threads):
30799
/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):
65530
/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):
32768
container (cgroup) information:
container_type: cgroupv1
cpu_cpuset_cpus: 0-1
cpu_memory_nodes: 0
active_processor_count: 2
cpu_quota: -1
cpu_period: 100000
cpu_shares: -1
memory_limit_in_bytes: -1
memory_and_swap_limit_in_bytes: -1
memory_soft_limit_in_bytes: -1
memory_usage_in_bytes: 3889819648
memory_max_usage_in_bytes: 0
CPU:total 2 (initial active 2) (2 cores per cpu, 2 threads per core) family 6 model 85 stepping 4, cmov, cx8, fxsr, mmx, sse, sse2, sse3, ssse3, sse4.1, sse4.2, popcnt, avx, avx2, aes, clmul, erms, rtm, 3dnowpref, lzcnt, ht, tsc, tscinvbit, bmi1, bmi2, adx, fma
CPU Model and flags from /proc/cpuinfo:
model name : Intel(R) Xeon(R) Platinum 8175M CPU @ 2.50GHz
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves ida arat pku ospke
Memory: 4k page, physical 3978224k(103460k free), swap 0k(0k free)
vm_info: OpenJDK 64-Bit Server VM (11+28) for linux-amd64 JRE (11+28), built on Aug 22 2018 18:55:06 by "mach5one" with gcc 7.3.0
END.
