Why Apache can heavily overload the system?

Question

linux

mysql freezes, what can these logs say?

[    4.068805] vmxnet3 0000:0b:00.0 ens192: intr type 3, mode 0, 5 vectors allocated
[    4.068863] vmxnet3 0000:0b:00.0 ens192: NIC Link is Up 10000 Mbps
[   23.208786] TCP: ens192: Driver has suspect GRO implementation, TCP performance may be compromised.
[80966.191750] INFO: rcu_sched detected stalls on CPUs/tasks:
[80966.292286] 	2-...: (1 GPs behind) idle=fa1/1/0 softirq=411806/411807 fqs=387 
[80966.292372] 	(detected by 1, t=5418 jiffies, g=990675, c=990674, q=587)
[80966.292455] Task dump for CPU 2:
[80966.292457] swapper/2       R  running task        0     0      1 0x00000008
[80966.296115]  000000010133a1fc 0000000000000000 0000000000000001 0100000000000000
[80966.296117]  ffffffff922141e0 0000000000000000 0000000000000000 0000000000000000
[80966.296119]  0000000000000000 ffffffffffffff04 ffffffff922144b2 0000000000000010
[80966.296120] Call Trace:
[80966.414753]  [<ffffffff922141e0>] ? __sched_text_end+0x1/0x1
[80966.414757]  [<ffffffff922144b2>] ? native_safe_halt+0x2/0x10
[80966.414758]  [<ffffffff922141fa>] ? default_idle+0x1a/0xd0
[80966.449804]  [<ffffffff91cbbd9a>] ? cpu_startup_entry+0x1ca/0x240
[80966.459246]  [<ffffffff91c48bb0>] ? start_secondary+0x170/0x1b0
[80972.322032] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [swapper/2:0]
[80972.322142] Modules linked in: crct10dif_pclmul crc32_pclmul ghash_clmulni_intel evdev vmw_balloon joydev pcspkr intel_rapl_perf serio_raw sg vmwgfx ttm shpchp drm_kms_helper drm vmw_vmci ac button ip_tables x_tables autofs4 hid_generic ext4 usbhid crc16 jbd2 crc32c_generic hid fscrypto ecb mbcache sr_mod cdrom sd_mod ata_generic crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd uhci_hcd ehci_pci psmouse ahci ehci_hcd ata_piix libahci vmw_pvscsi libata vmxnet3 usbcore scsi_mod usb_common i2c_piix4
[80972.449851] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.0-7-amd64 #1 Debian 4.9.110-3+deb9u2
[80972.449852] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
[80972.449854] task: ffff979c3a57b040 task.stack: ffffaef90069c000
[80972.449854] RIP: 0010:[<ffffffff922147f1>]  [<ffffffff922147f1>] _raw_spin_unlock_irqrestore+0x11/0x20
[80972.449894] RSP: 0018:ffff979c3fd03d48  EFLAGS: 00000286
[80972.449895] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000001000
[80972.449896] RDX: ffffaef900948000 RSI: 0000000000000286 RDI: 0000000000000286
[80972.449896] RBP: ffff979c395da4c0 R08: 0000000000000001 R09: 0000000000000000
[80972.449897] R10: ffff979b920adfe0 R11: ffff979c356a6000 R12: ffff979c36060000
[80972.449898] R13: ffff979c36060000 R14: ffff979c360607c4 R15: ffff979c356e5d50
[80972.449899] FS:  0000000000000000(0000) GS:ffff979c3fd00000(0000) knlGS:0000000000000000
[80972.449900] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[80972.449901] CR2: 000024d512498000 CR3: 0000000136556000 CR4: 0000000000160670
[80972.453204] Stack:
[80972.453207]  ffffffffc0289329 0000000000000286 0000000000000006 ffff979c36060858
[80972.453209]  ffffffffc0207c90 ffff979c356e5d40 ffff979c356a6000 ffff979b920ad000
[80972.453211]  ffff979c395da4c0 ffff979c36060000 ffff979c36060000 ffff979c35558030
[80972.453212] Call Trace:
[80972.456293]  <IRQ> 
[80972.456360]  [<ffffffffc0289329>] ? pvscsi_queue+0x439/0x880 [vmw_pvscsi]
[80972.486180]  [<ffffffffc0207c90>] ? scsi_test_unit_ready+0x150/0x150 [scsi_mod]
[80972.486187]  [<ffffffffc0205e22>] ? scsi_dispatch_cmd+0xe2/0x210 [scsi_mod]
[80972.486191]  [<ffffffffc0208bd0>] ? scsi_request_fn+0x460/0x5e0 [scsi_mod]
[80972.486193]  [<ffffffff91cbb024>] ? __wake_up+0x34/0x50
[80972.500714]  [<ffffffff91eff915>] ? __blk_run_queue+0x35/0x40
[80972.500716]  [<ffffffff91eff941>] ? blk_run_queue+0x21/0x40
[80972.500721]  [<ffffffffc0205973>] ? scsi_run_queue+0x243/0x2c0 [scsi_mod]
[80972.500725]  [<ffffffffc0206b82>] ? scsi_end_request+0x122/0x1a0 [scsi_mod]
[80972.500738]  [<ffffffffc0208f66>] ? scsi_io_completion+0x1a6/0x670 [scsi_mod]
[80972.506937]  [<ffffffff91f0ad3e>] ? blk_done_softirq+0x8e/0xc0
[80972.511810]  [<ffffffff922186ba>] ? __do_softirq+0x10a/0x29e
[80972.516679]  [<ffffffff91c7eefe>] ? irq_exit+0xae/0xb0
[80972.516682]  [<ffffffff922170b6>] ? call_function_single_interrupt+0x96/0xa0
[80972.516682]  <EOI> 
[80972.516684]  [<ffffffff922141e0>] ? __sched_text_end+0x1/0x1
[80972.516685]  [<ffffffff922144b2>] ? native_safe_halt+0x2/0x10
[80972.516687]  [<ffffffff922141fa>] ? default_idle+0x1a/0xd0
[80972.516688]  [<ffffffff91cbbd9a>] ? cpu_startup_entry+0x1ca/0x240
[80972.516690]  [<ffffffff91c48bb0>] ? start_secondary+0x170/0x1b0
[80972.516691] Code: 08 74 0b 65 81 25 7c b3 df 6d ff ff ff 7f 89 d0 c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 c6 07 00 0f 1f 40 00 48 89 f7 57 9d <0f> 1f 44 00 00 c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 c6 
[81145.701943] INFO: rcu_sched self-detected stall on CPU
[81145.710056] INFO: rcu_sched detected stalls on CPUs/tasks:
[81145.710065] 	1-...: (1 GPs behind) idle=6e7/140000000000001/0 softirq=579257/579257 fqs=98 
[81145.710065] 	
[81145.710067] (detected by 2, t=5294 jiffies, g=992377, c=992376, q=867)
[81145.710069] Task dump for CPU 1:
[81145.710070] ksoftirqd/1     R
[81145.710071]   running task    
[81145.710073]     0    16      2 0x00000008
[81145.710077]  ffff979b9209aed8
[81145.710077]  ffff979bac248638
[81145.710078]  ef59f5c5fe97e564
[81145.710078]  0000000000000004
[81145.710079]  0000000000000004
[81145.710080]  0000000000000018
[81145.718189]  ffffffff922186ba
[81145.718193]  000000a400000000
[81145.718193]  ffffffff92805110
[81145.718194]  0000010000000003
[81145.718194]  0000000101345c3d
[81145.718194]  ffff979c3a5a1040
[81145.718195] Call Trace:

Answer 1

not enough logs