我维护的网站有时会在某些资源上收到失败的 GET 请求。状态返回为 (failed)，类型为 Pending。标头仅包含请求本身，没有任何响应。
服务器正在运行 Drupal 和 Varnish。
关于导致失败的原因或从哪里开始调试的任何想法？
这可能与Chrome 在“Status = (failed)”和“Type = undefined”时遇到什么样的网络错误有关，即使类型返回不同的消息。有人可以证实这一点吗？如果是这样，我该如何调试呢？
提前致谢
编辑，我刚刚安装了wireshark 来尝试调试更多。
这是失败请求的全部后续内容
94645、94651、94686 和 94688 的转储
No. Time Source Destination Protocol Length Info
94645 211.219995 192.168.0.101 85.134.37.196 HTTP 1192 [TCP Retransmission] GET /sites/default/files/css/css_4PXz_aZSHtm7FWHqYsMdm7sl9C4802BFn9tXlePfpJU.css HTTP/1.1
Frame 94645: 1192 bytes on wire (9536 bits), 1192 bytes captured (9536 bits)
Arrival Time: Nov 7, 2012 22:55:18.002267000 EET
Epoch Time: 1352321718.002267000 seconds
[Time delta from previous captured frame: 0.006199000 seconds]
[Time delta from previous displayed frame: 0.815800000 seconds]
[Time since reference or first frame: 211.219995000 seconds]
Frame Number: 94645
Frame Length: 1192 bytes (9536 bits)
Capture Length: 1192 bytes (9536 bits)
[Frame is marked: True]
[Frame is ignored: False]
[Protocols in frame: eth:ip:tcp:http]
[Coloring Rule Name: Bad TCP]
[Coloring Rule String: tcp.analysis.flags]
Ethernet II, Src: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f), Dst: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
Destination: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
Address: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Source: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
Address: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Type: IP (0x0800)
Internet Protocol Version 4, Src: 192.168.0.101 (192.168.0.101), Dst: 85.134.37.196 (85.134.37.196)
Version: 4
Header length: 20 bytes
Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
0000 00.. = Differentiated Services Codepoint: Default (0x00)
.... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
Total Length: 1178
Identification: 0x4e23 (20003)
Flags: 0x02 (Don't Fragment)
0... .... = Reserved bit: Not set
.1.. .... = Don't fragment: Set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 64
Protocol: TCP (6)
Header checksum: 0xabe3 [correct]
[Good: True]
[Bad: False]
Source: 192.168.0.101 (192.168.0.101)
Destination: 85.134.37.196 (85.134.37.196)
Transmission Control Protocol, Src Port: 51714 (51714), Dst Port: http (80), Seq: 1, Ack: 1, Len: 1126
Source port: 51714 (51714)
Destination port: http (80)
[Stream index: 5205]
Sequence number: 1 (relative sequence number)
[Next sequence number: 1127 (relative sequence number)]
Acknowledgement number: 1 (relative ack number)
Header length: 32 bytes
Flags: 0x018 (PSH, ACK)
000. .... .... = Reserved: Not set
...0 .... .... = Nonce: Not set
.... 0... .... = Congestion Window Reduced (CWR): Not set
.... .0.. .... = ECN-Echo: Not set
.... ..0. .... = Urgent: Not set
.... ...1 .... = Acknowledgement: Set
.... .... 1... = Push: Set
.... .... .0.. = Reset: Not set
.... .... ..0. = Syn: Not set
.... .... ...0 = Fin: Not set
Window size value: 229
[Calculated window size: 14656]
[Window size scaling factor: 64]
Checksum: 0xb15e [validation disabled]
[Good Checksum: False]
[Bad Checksum: False]
Options: (12 bytes)
No-Operation (NOP)
No-Operation (NOP)
Timestamps: TSval 30409363, TSecr 1723048723
Kind: Timestamp (8)
Length: 10
Timestamp value: 30409363
Timestamp echo reply: 1723048723
[SEQ/ACK analysis]
[Bytes in flight: 1126]
[TCP Analysis Flags]
[This frame is a (suspected) retransmission]
[Expert Info (Note/Sequence): Retransmission (suspected)]
[Message: Retransmission (suspected)]
[Severity level: Note]
[Group: Sequence]
[The RTO for this segment was: 1.480371000 seconds]
[RTO based on delta from frame: 92823]
Hypertext Transfer Protocol
GET /sites/default/files/css/css_4PXz_aZSHtm7FWHqYsMdm7sl9C4802BFn9tXlePfpJU.css HTTP/1.1\r\n
[Expert Info (Chat/Sequence): GET /sites/default/files/css/css_4PXz_aZSHtm7FWHqYsMdm7sl9C4802BFn9tXlePfpJU.css HTTP/1.1\r\n]
[Message: GET /sites/default/files/css/css_4PXz_aZSHtm7FWHqYsMdm7sl9C4802BFn9tXlePfpJU.css HTTP/1.1\r\n]
[Severity level: Chat]
[Group: Sequence]
Request Method: GET
Request URI: /sites/default/files/css/css_4PXz_aZSHtm7FWHqYsMdm7sl9C4802BFn9tXlePfpJU.css
Request Version: HTTP/1.1
Host: www.snellman.fi\r\n
Connection: keep-alive\r\n
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4\r\n
Accept: text/css,*/*;q=0.1\r\n
Referer: http://www.snellman.fi/sv\r\n
Accept-Encoding: gzip,deflate,sdch\r\n
Accept-Language: en-US,en;q=0.8\r\n
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n
[truncated] Cookie: v_tid=82524dc4552b4cd4a22d1fa4e7e78d72; Drupal.toolbar.collapsed=0; ctools-collapsible-state=views-ui-advanced-column-uusimmat_reseptit%3A1%2Cviews-ui-advanced-column-Related%3A1; Drupal.tableDrag.showWeight=0; SESS4049
\r\n
[Full request URI: http://www.snellman.fi/sites/default/files/css/css_4PXz_aZSHtm7FWHqYsMdm7sl9C4802BFn9tXlePfpJU.css]
---------------------------------------------------------------------------------------------------------------------------------------------------------
No. Time Source Destination Protocol Length Info
94651 211.228592 85.134.37.196 192.168.0.101 TCP 66 [TCP Dup ACK 92860#3] http > 51714 [ACK] Seq=1 Ack=1 Win=14592 Len=0 TSval=1723049571 TSecr=1723044620
Frame 94651: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Arrival Time: Nov 7, 2012 22:55:18.010864000 EET
Epoch Time: 1352321718.010864000 seconds
[Time delta from previous captured frame: 0.001166000 seconds]
[Time delta from previous displayed frame: 0.008597000 seconds]
[Time since reference or first frame: 211.228592000 seconds]
Frame Number: 94651
Frame Length: 66 bytes (528 bits)
Capture Length: 66 bytes (528 bits)
[Frame is marked: True]
[Frame is ignored: False]
[Protocols in frame: eth:ip:tcp]
[Coloring Rule Name: Bad TCP]
[Coloring Rule String: tcp.analysis.flags]
Ethernet II, Src: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4), Dst: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
Destination: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
Address: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Source: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
Address: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Type: IP (0x0800)
Internet Protocol Version 4, Src: 85.134.37.196 (85.134.37.196), Dst: 192.168.0.101 (192.168.0.101)
Version: 4
Header length: 20 bytes
Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
0000 00.. = Differentiated Services Codepoint: Default (0x00)
.... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
Total Length: 52
Identification: 0x8b62 (35682)
Flags: 0x02 (Don't Fragment)
0... .... = Reserved bit: Not set
.1.. .... = Don't fragment: Set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 58
Protocol: TCP (6)
Header checksum: 0x790a [correct]
[Good: True]
[Bad: False]
Source: 85.134.37.196 (85.134.37.196)
Destination: 192.168.0.101 (192.168.0.101)
Transmission Control Protocol, Src Port: http (80), Dst Port: 51714 (51714), Seq: 1, Ack: 1, Len: 0
Source port: http (80)
Destination port: 51714 (51714)
[Stream index: 5205]
Sequence number: 1 (relative sequence number)
Acknowledgement number: 1 (relative ack number)
Header length: 32 bytes
Flags: 0x010 (ACK)
000. .... .... = Reserved: Not set
...0 .... .... = Nonce: Not set
.... 0... .... = Congestion Window Reduced (CWR): Not set
.... .0.. .... = ECN-Echo: Not set
.... ..0. .... = Urgent: Not set
.... ...1 .... = Acknowledgement: Set
.... .... 0... = Push: Not set
.... .... .0.. = Reset: Not set
.... .... ..0. = Syn: Not set
.... .... ...0 = Fin: Not set
Window size value: 114
[Calculated window size: 14592]
[Window size scaling factor: 128]
Checksum: 0xd246 [validation disabled]
[Good Checksum: False]
[Bad Checksum: False]
Options: (12 bytes)
No-Operation (NOP)
No-Operation (NOP)
Timestamps: TSval 1723049571, TSecr 1723044620
Kind: Timestamp (8)
Length: 10
Timestamp value: 1723049571
Timestamp echo reply: 1723044620
[SEQ/ACK analysis]
[TCP Analysis Flags]
[This is a TCP duplicate ack]
[Duplicate ACK #: 3]
[Duplicate to the ACK in frame: 92860]
[Expert Info (Note/Sequence): Duplicate ACK (#3)]
[Message: Duplicate ACK (#3)]
[Severity level: Note]
[Group: Sequence]
---------------------------------------------------------------------------------------------------------------------------------------------------------
No. Time Source Destination Protocol Length Info
94686 211.305208 85.134.37.196 192.168.0.101 TCP 66 http > 51714 [FIN, ACK] Seq=1 Ack=1 Win=14592 Len=0 TSval=1723049647 TSecr=1723044620
Frame 94686: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Arrival Time: Nov 7, 2012 22:55:18.087480000 EET
Epoch Time: 1352321718.087480000 seconds
[Time delta from previous captured frame: 0.000026000 seconds]
[Time delta from previous displayed frame: 0.076616000 seconds]
[Time since reference or first frame: 211.305208000 seconds]
Frame Number: 94686
Frame Length: 66 bytes (528 bits)
Capture Length: 66 bytes (528 bits)
[Frame is marked: True]
[Frame is ignored: False]
[Protocols in frame: eth:ip:tcp]
[Coloring Rule Name: HTTP]
[Coloring Rule String: http || tcp.port == 80]
Ethernet II, Src: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4), Dst: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
Destination: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
Address: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Source: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
Address: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Type: IP (0x0800)
Internet Protocol Version 4, Src: 85.134.37.196 (85.134.37.196), Dst: 192.168.0.101 (192.168.0.101)
Version: 4
Header length: 20 bytes
Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
0000 00.. = Differentiated Services Codepoint: Default (0x00)
.... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
Total Length: 52
Identification: 0x8b63 (35683)
Flags: 0x02 (Don't Fragment)
0... .... = Reserved bit: Not set
.1.. .... = Don't fragment: Set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 58
Protocol: TCP (6)
Header checksum: 0x7909 [correct]
[Good: True]
[Bad: False]
Source: 85.134.37.196 (85.134.37.196)
Destination: 192.168.0.101 (192.168.0.101)
Transmission Control Protocol, Src Port: http (80), Dst Port: 51714 (51714), Seq: 1, Ack: 1, Len: 0
Source port: http (80)
Destination port: 51714 (51714)
[Stream index: 5205]
Sequence number: 1 (relative sequence number)
Acknowledgement number: 1 (relative ack number)
Header length: 32 bytes
Flags: 0x011 (FIN, ACK)
000. .... .... = Reserved: Not set
...0 .... .... = Nonce: Not set
.... 0... .... = Congestion Window Reduced (CWR): Not set
.... .0.. .... = ECN-Echo: Not set
.... ..0. .... = Urgent: Not set
.... ...1 .... = Acknowledgement: Set
.... .... 0... = Push: Not set
.... .... .0.. = Reset: Not set
.... .... ..0. = Syn: Not set
.... .... ...1 = Fin: Set
[Expert Info (Chat/Sequence): Connection finish (FIN)]
[Message: Connection finish (FIN)]
[Severity level: Chat]
[Group: Sequence]
Window size value: 114
[Calculated window size: 14592]
[Window size scaling factor: 128]
Checksum: 0xd1f9 [validation disabled]
[Good Checksum: False]
[Bad Checksum: False]
Options: (12 bytes)
No-Operation (NOP)
No-Operation (NOP)
Timestamps: TSval 1723049647, TSecr 1723044620
Kind: Timestamp (8)
Length: 10
Timestamp value: 1723049647
Timestamp echo reply: 1723044620
---------------------------------------------------------------------------------------------------------------------------------------------------------
No. Time Source Destination Protocol Length Info
94688 211.305660 192.168.0.101 85.134.37.196 TCP 66 51714 > http [FIN, ACK] Seq=1127 Ack=2 Win=14656 Len=0 TSval=30409384 TSecr=1723049647
Frame 94688: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Arrival Time: Nov 7, 2012 22:55:18.087932000 EET
Epoch Time: 1352321718.087932000 seconds
[Time delta from previous captured frame: 0.000264000 seconds]
[Time delta from previous displayed frame: 0.000452000 seconds]
[Time since reference or first frame: 211.305660000 seconds]
Frame Number: 94688
Frame Length: 66 bytes (528 bits)
Capture Length: 66 bytes (528 bits)
[Frame is marked: True]
[Frame is ignored: False]
[Protocols in frame: eth:ip:tcp]
[Coloring Rule Name: HTTP]
[Coloring Rule String: http || tcp.port == 80]
Ethernet II, Src: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f), Dst: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
Destination: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
Address: D-LinkIn_2f:a4:a4 (14:d6:4d:2f:a4:a4)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Source: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
Address: HonHaiPr_e7:39:2f (38:59:f9:e7:39:2f)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Type: IP (0x0800)
Internet Protocol Version 4, Src: 192.168.0.101 (192.168.0.101), Dst: 85.134.37.196 (85.134.37.196)
Version: 4
Header length: 20 bytes
Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
0000 00.. = Differentiated Services Codepoint: Default (0x00)
.... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
Total Length: 52
Identification: 0x4e24 (20004)
Flags: 0x02 (Don't Fragment)
0... .... = Reserved bit: Not set
.1.. .... = Don't fragment: Set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 64
Protocol: TCP (6)
Header checksum: 0xb048 [correct]
[Good: True]
[Bad: False]
Source: 192.168.0.101 (192.168.0.101)
Destination: 85.134.37.196 (85.134.37.196)
Transmission Control Protocol, Src Port: 51714 (51714), Dst Port: http (80), Seq: 1127, Ack: 2, Len: 0
Source port: 51714 (51714)
Destination port: http (80)
[Stream index: 5205]
Sequence number: 1127 (relative sequence number)
Acknowledgement number: 2 (relative ack number)
Header length: 32 bytes
Flags: 0x011 (FIN, ACK)
000. .... .... = Reserved: Not set
...0 .... .... = Nonce: Not set
.... 0... .... = Congestion Window Reduced (CWR): Not set
.... .0.. .... = ECN-Echo: Not set
.... ..0. .... = Urgent: Not set
.... ...1 .... = Acknowledgement: Set
.... .... 0... = Push: Not set
.... .... .0.. = Reset: Not set
.... .... ..0. = Syn: Not set
.... .... ...1 = Fin: Set
[Expert Info (Chat/Sequence): Connection finish (FIN)]
[Message: Connection finish (FIN)]
[Severity level: Chat]
[Group: Sequence]
Window size value: 229
[Calculated window size: 14656]
[Window size scaling factor: 64]
Checksum: 0x3c7e [validation disabled]
[Good Checksum: False]
[Bad Checksum: False]
Options: (12 bytes)
No-Operation (NOP)
No-Operation (NOP)
Timestamps: TSval 30409384, TSecr 1723049647
Kind: Timestamp (8)
Length: 10
Timestamp value: 30409384
Timestamp echo reply: 1723049647
[SEQ/ACK analysis]
[This is an ACK to the segment in frame: 94686]
[The RTT to ACK the segment was: 0.000452000 seconds]