我在运行Ubuntu的Homestead流浪盒子上执行PHP命令时一直挂起。在控制台开始执行php cli之前，有一个明显的延迟。
从流浪箱中取出strace -vyT -S time php artisan help。在第一次到最后一次呼叫recvfrom(3时，一切都卡住了几分钟，但我不知道为什么:
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 3 <0.000010>
fstat(3</run/resolvconf/resolv.conf>, {st_dev=makedev(0, 16), st_ino=7632, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=171, st_atime=2015/10/17-04:53:56, st_mtime=2015/10/17-04:53:54, st_ctime=2015/10/17-04:53:54}) = 0 <0.000007>
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fed9385c000 <0.000008>
read(3</run/resolvconf/resolv.conf>, "# Dynamic resolv.conf(5) file fo"..., 4096) = 171 <0.000010>
read(3</run/resolvconf/resolv.conf>, "", 4096) = 0 <0.000006>
close(3</run/resolvconf/resolv.conf>) = 0 <0.000008>
munmap(0x7fed9385c000, 4096) = 0 <0.000011>
uname({sysname="Linux", nodename="homestead", release="3.13.0-65-generic", version="#106-Ubuntu SMP Fri Oct 2 22:08:27 UTC 2015", machine="x86_64", domainname="(none)"}) = 0 <0.000006>
stat("/etc/resolv.conf", {st_dev=makedev(0, 16), st_ino=7632, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=171, st_atime=2015/10/17-04:53:56, st_mtime=2015/10/17-04:53:54, st_ctime=2015/10/17-04:53:54}) = 0 <0.000008>
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 3 <0.000009>
fstat(3</etc/hosts>, {st_dev=makedev(8, 1), st_ino=1161, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=251, st_atime=2015/10/16-18:57:29, st_mtime=2014/10/03-01:16:42, st_ctime=2014/10/03-01:16:42}) = 0 <0.000005>
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fed9385c000 <0.000008>
read(3</etc/hosts>, "127.0.0.1 localhost'n'n# The follo"..., 4096) = 251 <0.000009>
read(3</etc/hosts>, "", 4096) = 0 <0.000007>
close(3</etc/hosts>) = 0 <0.000007>
munmap(0x7fed9385c000, 4096) = 0 <0.000010>
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3 <0.000012>
fcntl(3<socket:[78362]>, F_SETFL, O_RDONLY|O_NONBLOCK) = 0 <0.000006>
connect(3, {sa_family=AF_INET, sin_port=htons(9000), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EINPROGRESS (Operation now in progress) <0.000094>
select(4, [3<socket:[78362]>], [3<socket:[78362]>], [3<socket:[78362]>], {0, 200000}) = 1 (out [3], left {0, 199997}) <0.000010>
getpeername(3, {sa_family=AF_INET, sin_port=htons(9000), sin_addr=inet_addr("127.0.0.1")}, [16]) = 0 <0.000007>
fcntl(3<socket:[78362]>, F_SETFL, O_RDONLY) = 0 <0.000006>
setsockopt(3, SOL_TCP, TCP_NODELAY, "'1'0'0'0'0'0'0'0", 8) = 0 <0.000008>
write(3<socket:[78362]>, "478'0<?xml version='"1.0'" encoding"..., 483) = 483 <0.000042>
brk(0x2f93000) = 0x2f93000 <0.000472>
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <4.940291>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.072574>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.033758>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.038904>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.026003>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.024057>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.055221>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.058240>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.027569>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.056877>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.025934>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.076699>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.089092>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.254680>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.131634>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.065721>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.042778>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.072277>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.044424>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) <0.080704>
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = -1 ECONNRESET (Connection reset by peer) <113.777721>
/etc/hosts的内容如下:
127.0.0.1 localhost
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
127.0.1.1 homestead homestead
/etc/resolve.conf含量:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 10.0.2.3
这个问题现在影响了我所有的不相关的流浪盒子，而不仅仅是Homestead盒子。几乎每台机器上的每条PHP命令在每次CLI执行时都会停顿5-15分钟。如果必须调用一个命令链，则可能需要一个小时才能完成本应只需要30秒的过程。
在运行这些盒子的Mac升级到El Capitan之后，这个问题就开始了。
根据流浪框的不同，有时会出现以下行:
connect(3, {sa_family=AF_INET, sin_port=htons(9000), sin_addr=inet_addr("127.0.0.1")}, 16) = 0
被替换为:
connect(3, {sa_family=AF_INET, sin_port=htons(9000), sin_addr=inet_addr("192.168.56.1")}, 16) = 0
IP 192.168.56.1似乎是VirtualBox的默认路由器。
请注意，所有的流浪框要么是标准配置，要么是那些在我的其他团队成员的Mac/Windows系统上没有问题的。
Vagrant 1.7.4和VirtualBox 4.3.30.
响应请求route -n:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.0.2.2 0.0.0.0 UG 0 0 0 eth0
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.10.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
sudo netstat -tulnp | grep 9000结果:
tcp6 0 0 :::9000 :::* LISTEN 1317/hhvm
为什么hhvm出现，我不知道，因为盒子应该使用标准的PHP解释器
tl;dr:我怪xdebug客户端。尝试在Ubuntu上禁用xdebug。
<<p> 我的理由/strong>:我在strace日志中没有看到主机解析有任何问题。
首先检查/etc/resolv.conf，然后检查/etc/hosts，然后连接到127.0.0.1:9000 connect(3, {sa_family=AF_INET, sin_port=htons(9000), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EINPROGRESS (Operation now in progress) <0.000094>
端口9000是xdebug的默认值，除非在/etc/php5/mods-available/xdebug.ini或类似的版本中重新定义。
write(3<socket:[78362]>, "478'0<?xml version='"1.0'" encoding"..., 483) = 483 <0.000042>看起来像从xdebug扩展发送到客户端的消息。
它等待2分钟recvfrom(3, 0x7ffc489b16d0, 128, 0, 0, 0) = ? ERESTARTSYS，然后放弃并执行php脚本。
从v2.2.4开始等待时间减少到200 ms: https://github.com/xdebug/xdebug/pull/90
假设禁用xdebug可以解决问题，这里有几个选项:
- 配置xdebug为只使用
xdebug.remote_autostart=off按需启动 - 继续启用/禁用xdebug
- 保持xdebug客户端始终打开，并确保端口映射正确，并且它不会挂起
问题似乎与主机名解析有关。如果您正在尝试使用您的ip而不是本地主机ip 127.0.0.1。最好在/etc/hosts中使用，如:
yourip hostname.example.com hostname
例如
10.0.2.20 test.example.com test
，将localhost从/etc/hosts中移除或保留。系统将尝试获取第一个条目，如果您不使用ipv6，那么您也可以删除ipv6相关条目。
你的/etc/resolv.conf文件应该有以下行
nameserver 127.0.0.1
还添加了vagrant默认网络，因为你的输出显示它试图连接它，但如果你不想使用，你可以跳过。你正在使用127.0.0.1，所以至少它应该在那里。
感觉像是DNS问题。我的猜测是，您的机器无法通过给定的主机名解析DNS，或者DNS服务器速度太慢。我的建议是在本地安装一个缓存DNS服务器，并使用它，并在/etc/hosts文件中添加私有网络中的任何不会从DNS提供服务的内容。使用NetworkManager或任何您必须添加127.0.0.1作为可行(和首选)DNS服务器的网络服务，事情应该会顺利进行。如果你使用的是ubuntu，那就像sudo apt-get install bind9一样简单。
如果你想诊断问题，首先安装dnsutils，获取dig和nslookup，并尝试查询一些东西，比如www.google.co.uk，看看需要多长时间以及哪个服务器是权威的。然后尝试使用dig，更具体地说，直接询问服务器，直接询问SOA，看看是否能找出最薄弱的环节在哪里。
这可能是一个路由器，它通过DHCP将自己作为DNS服务发布，但在按下时不能正常工作。