Estou recebendo reclamações de usuários sobre o desempenho insatisfatório de aplicativos de rede entre duas partes de um grande depósito. O software é um aplicativo terminal baseado em curses em execução em um servidor Linux. Os clientes são PCs que executam um cliente telnet ou SSH. O problema começou há um dia sem alterações recentes (conhecidas) no ambiente.
O switch central é um Cisco Catalyst 4507R-E no MDF , vinculado a uma pilha de 4 membros dos switches Cisco Catalyst 2960 no IDF ... Eles estão conectados via fibra multimodo. Os servidores estão no MDF. Os clientes impactados estão no IDF.
O ping do servidor de aplicativos do Linux para o endereço de gerenciamento da pilha 2960 no prédio mostra alta variação e um lote de latência:
--- shipping-2960.mdmarra.local ping statistics ---
864 packets transmitted, 864 received, 0% packet loss, time 863312ms
rtt min/avg/max/mdev = 0.521/5.317/127.037/8.698 ms
No entanto, os pings para os computadores clientes do servidor de aplicativos são um pouco mais consistentes:
--- charles-pc.mdmarra.local ping statistics ---
76 packets transmitted, 76 received, 0% packet loss, time 75001ms
rtt min/avg/max/mdev = 0.328/0.481/1.355/0.210 ms
Nenhuma das interfaces relevantes do Linux ou switchports mostram erros ( veja abaixo da questão ).
Como posso solucionar isso?
- Existe um método fácil para determinar a atividade da porta?
- A variação do ping no IP de gerenciamento do switch é a coisa errada a ser medida?
- Este poderia ser o resultado de um PC desonesto?
- Como o problema está isolado em uma parte do edifício, há algo mais que eu deveria estar verificando? Outros usuários no warehouse estão bem e não tiveram problemas.
Editar:
Mais tarde, descobri que a utilização da CPU do Cisco 2960 é extremamente alta devido ao bug detalhado aqui .
Da pilha 2960 ...
shipping-2960#sh int GigabitEthernet1/0/52
GigabitEthernet1/0/52 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is b414.894a.09b4 (bia b414.894a.09b4)
Description: TO_MDF_4507
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 13/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseSX SFP
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 441
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 3053000 bits/sec, 613 packets/sec
5 minute output rate 51117000 bits/sec, 4815 packets/sec
981767797 packets input, 615324451566 bytes, 0 no buffer
Received 295141786 broadcasts (286005510 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 286005510 multicast, 0 pause input
0 input packets with dribble condition detected
6372280523 packets output, 8375642643516 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
Saída adicional:
Utilização de CPU do Cisco 4507R-E - classificada.
Utilização da CPU do Cisco 2960 - classificada.
utilização de tcam de 2960. Não disponível no 4507.
shipping-2960# show platform tcam utilization
CAM Utilization for ASIC# 0 Max Used
Masks/Values Masks/values
Unicast mac addresses: 8412/8412 335/335
IPv4 IGMP groups + multicast routes: 384/384 1/1
IPv4 unicast directly-connected routes: 320/320 28/28
IPv4 unicast indirectly-connected routes: 0/0 28/28
IPv6 Multicast groups: 320/320 11/11
IPv6 unicast directly-connected routes: 256/256 1/1
IPv6 unicast indirectly-connected routes: 0/0 1/1
IPv4 policy based routing aces: 32/32 12/12
IPv4 qos aces: 384/384 42/42
IPv4 security aces: 384/384 33/33
IPv6 policy based routing aces: 16/16 8/8
IPv6 qos aces: 60/60 31/31
IPv6 security aces: 128/128 9/9
histórico de utilização da CPU do Cisco 2960 ...
shipping-2960#show processes cpu history
3333333444443333344444444443333333333444443333344444444443
9977777111119999966666222229999977777555559999911111000008
100
90
80
70
60
50 ***** *****
40 **********************************************************
30 **********************************************************
20 **********************************************************
10 **********************************************************
0....5....1....1....2....2....3....3....4....4....5....5....
0 5 0 5 0 5 0 5 0 5
CPU% per second (last 60 seconds)
4488887787444454444787888444444454677774444444447888544444
6401207808656506776708000447546664789977697589953201636647
100
90
80 *###*##* *#*##* *#** ###
70 #######* *##### *###* *###
60 #######* *##### * *#### *###*
50 * ########*********###### ** *** *####*********####* ** *
40 ##########################################################
30 ##########################################################
20 ##########################################################
10 ##########################################################
0....5....1....1....2....2....3....3....4....4....5....5....
0 5 0 5 0 5 0 5 0 5
CPU% per minute (last 60 minutes)
* = maximum CPU% # = average CPU%
8889888888888888988888889888888888888888888888888888888888888888898889
2322334378633453364454472653323431254225563228261399243233354222402310
100
90 * *** * ** * **** * *** * * ** * * *
80 *#############################*********************************#******
70 *#####################################################################
60 *#####################################################################
50 ######################################################################
40 ######################################################################
30 ######################################################################
20 ######################################################################
10 ######################################################################
0....5....1....1....2....2....3....3....4....4....5....5....6....6....7.
0 5 0 5 0 5 0 5 0 5 0 5 0
CPU% per hour (last 72 hours)
* = maximum CPU% # = average CPU%
