为了在 PHP 中进行开发，我使用具有嵌入式 FTP 客户端的 PHPStorm IDE。每当我将文件上传到 FTP 服务器时，都会出现 2-5 秒的延迟，这导致文件上传需要大约 10-15 秒。它必须与 SSL 相关，无论是网络协议还是 FTP 客户端对服务器证书的验证。每当我切换到 FTP 时，上传速度都快如闪电。我还应该补充一点，当我连接到不同的客户端（FileZilla）时，上传和下载工作非常好。我已经排除了 UseIPv6 和 IdentLookups 选项，关闭它们没有任何效果。我以被动模式连接，因此也不会造成任何问题。
我没有想法，真的可以使用一些帮助！谢谢。
FTP 服务器是 Debian Wheezy 机器上的 proftpd 1.3.4a。
proftpd.conf：
Include /etc/proftpd/modules.conf
UseIPv6 on
IdentLookups on
ServerName "domain.tld"
ServerType standalone
DeferWelcome on
MultilineRFC2228 on
DefaultServer on
ShowSymlinks on
TimeoutNoTransfer 600
TimeoutStalled 600
TimeoutIdle 1200
DisplayLogin welcome.msg
DisplayChdir .message true
ListOptions "-l"
DenyFilter \*.*/
DefaultRoot ~
RequireValidShell on
Port 21
PassivePorts 49152 65534
MaxInstances 30
Umask 027 027
AllowOverwrite on
AuthOrder mod_sql.c
# UseSendFile off
<IfModule mod_quotatab.c>
QuotaEngine off
</IfModule>
<IfModule mod_ratio.c>
Ratios off
</IfModule>
<IfModule mod_delay.c>
DelayEngine off
</IfModule>
#
# Alternative authentication frameworks
#
#Include /etc/proftpd/ldap.conf
Include /etc/proftpd/sql.conf
#
# This is used for FTPS connections
#
Include /etc/proftpd/tls.conf
tls.conf：
<IfModule mod_tls.c>
TLSEngine on
TLSLog /var/log/proftpd/tls.log
TLSProtocol SSLv3 TLSv1
TLSRSACertificateFile /etc/ssl/localcerts/domain_tld.crt
TLSRSACertificateKeyFile /etc/ssl/localcerts/domain_tld.key
TLSCACertificatePath /etc/ssl/certs/
TLSOptions NoCertRequest EnableDiags NoSessionReuseRequired
#TLSVerifyClient on
TLSRequired auth
#TLSRenegotiate required off
</IfModule>
最后，通过 PHPStorm IDE 上传文件的 tls.log：
Aug 30 08:56:46 mod_tls/2.4.3[8365]: TLSOption EnableDiags enabled, setting diagnostics callback
Aug 30 08:56:46 mod_tls/2.4.3[8365]: TLS/TLS-C requested, starting TLS handshake
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: before/accept initialization
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: unknown state
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientHello' Handshake message (149 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client hello A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHello' Handshake message (81 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server hello A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Certificate' Handshake message (1299 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write certificate A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHelloDone' Handshake message (4 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server done A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientKeyExchange' Handshake message (262 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client key exchange A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] received TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] received TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read finished A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] sent TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write change cipher spec A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write finished A
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] ok: SSL negotiation finished successfully
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: SSL negotiation finished successfully
Aug 30 08:56:46 mod_tls/2.4.3[8365]: client supports secure renegotiations
Aug 30 08:56:46 mod_tls/2.4.3[8365]: TLSv1/SSLv3 connection accepted, using cipher AES128-SHA (128 bits)
Aug 30 08:56:46 mod_tls/2.4.3[8365]: Protection set to Private
Aug 30 08:56:46 mod_tls/2.4.3[8365]: starting TLS negotiation on data connection
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: before/accept initialization
Aug 30 08:56:46 mod_tls/2.4.3[8365]: [info] accepting: unknown state
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientHello' Handshake message (149 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client hello A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHello' Handshake message (81 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server hello A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Certificate' Handshake message (1299 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write certificate A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHelloDone' Handshake message (4 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server done A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client certificate A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client certificate A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientKeyExchange' Handshake message (262 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client key exchange A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read certificate verify A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] received TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] received TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read finished A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] sent TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write change cipher spec A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write finished A
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:50 mod_tls/2.4.3[8365]: TLSv1/SSLv3 renegotiation accepted, using cipher AES128-SHA (128 bits)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] ok: SSL negotiation finished successfully
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: SSL negotiation finished successfully
Aug 30 08:56:50 mod_tls/2.4.3[8365]: TLSv1/SSLv3 data connection accepted, using cipher AES128-SHA (128 bits)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [msg] sent TLSv1 warning 'close_notify' Alert message (2 bytes)
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] writing: SSL/TLS alert warning: close notify
Aug 30 08:56:50 mod_tls/2.4.3[8365]: starting TLS negotiation on data connection
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: before/accept initialization
Aug 30 08:56:50 mod_tls/2.4.3[8365]: [info] accepting: unknown state
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientHello' Handshake message (149 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client hello A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHello' Handshake message (81 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server hello A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Certificate' Handshake message (1299 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write certificate A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHelloDone' Handshake message (4 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server done A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client certificate A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client certificate A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientKeyExchange' Handshake message (262 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client key exchange A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read certificate verify A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] received TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] received TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read finished A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] sent TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write change cipher spec A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write finished A
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:52 mod_tls/2.4.3[8365]: TLSv1/SSLv3 renegotiation accepted, using cipher AES128-SHA (128 bits)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] ok: SSL negotiation finished successfully
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: SSL negotiation finished successfully
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] received TLSv1 warning 'close_notify' Alert message (2 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] reading: SSL/TLS alert warning: close notify
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [msg] sent TLSv1 warning 'close_notify' Alert message (2 bytes)
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] writing: SSL/TLS alert warning: close notify
Aug 30 08:56:52 mod_tls/2.4.3[8365]: starting TLS negotiation on data connection
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: before/accept initialization
Aug 30 08:56:52 mod_tls/2.4.3[8365]: [info] accepting: unknown state
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientHello' Handshake message (149 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client hello A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHello' Handshake message (81 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server hello A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Certificate' Handshake message (1299 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write certificate A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'ServerHelloDone' Handshake message (4 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write server done A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client certificate A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client certificate A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] received TLSv1 'ClientKeyExchange' Handshake message (262 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read client key exchange A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read certificate verify A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] received TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] received TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 read finished A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] sent TLSv1 ChangeCipherSpec message (1 byte)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write change cipher spec A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] sent TLSv1 'Finished' Handshake message (16 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 write finished A
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSLv3 flush data
Aug 30 08:56:54 mod_tls/2.4.3[8365]: TLSv1/SSLv3 renegotiation accepted, using cipher AES128-SHA (128 bits)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] ok: SSL negotiation finished successfully
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] accepting: SSL negotiation finished successfully
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [msg] sent TLSv1 warning 'close_notify' Alert message (2 bytes)
Aug 30 08:56:54 mod_tls/2.4.3[8365]: [info] writing: SSL/TLS alert warning: close notify