Compression issue

[Char]

Today i debug remote host over bad channel. step over command runs slowly compression settings don`t change speed.

I want to check it – is VisualGDB  support compression – change sshd settings to

LogLevel DEBUG2

check again my host settings

and  SmartTTY compression  does not work on centos 7!

🙁 i check logs and have two solutions –

1. you should update libssh to 1.4.3 or more late and enanable ‘zlib@openssh.com’ copmression type
2. disable uncmpressed SSH at server-side https://snippets.khromov.se/enable-zlib-compression-in-sshd-on-centos/

here is my log:

Apr 21 05:04:48 lcnt sshd[11317]: debug1: Forked child 11503.
Apr 21 05:04:48 lcnt sshd[11503]: Set /proc/self/oom_score_adj to 0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: rexec start in 5 out 5 newsock 5 pipe 7 sock 8
Apr 21 05:04:48 lcnt sshd[11503]: debug1: inetd sockets after dupping: 3, 3
Apr 21 05:04:48 lcnt sshd[11503]: Connection from 192.168.206.1 port 9304 on 192.168.206.129 port 22
Apr 21 05:04:48 lcnt sshd[11503]: debug1: Client protocol version 2.0; client software version libssh2_1.4.2
Apr 21 05:04:48 lcnt sshd[11503]: debug1: no match: libssh2_1.4.2
Apr 21 05:04:48 lcnt sshd[11503]: debug1: Enabling compatibility mode for protocol 2.0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: Local version string SSH-2.0-OpenSSH_6.6.1
Apr 21 05:04:48 lcnt sshd[11503]: debug2: fd 3 setting O_NONBLOCK
Apr 21 05:04:48 lcnt sshd[11503]: debug2: Network child is on pid 11504
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SELinux support enabled [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: permanently_set_uid: 74/74 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: list_hostkey_types: ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SSH2_MSG_KEXINIT sent [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SSH2_MSG_KEXINIT received [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: none,zlib@openssh.com [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: none,zlib@openssh.com [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: first_kex_follows 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: reserved 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: ssh-rsa,ssh-dss [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,blowfish-cbc,arcfour128,arcfour,cast128-cbc,3des-cbc [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,blowfish-cbc,arcfour128,arcfour,cast128-cbc,3des-cbc [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-ripemd160@openssh.com [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-ripemd160@openssh.com [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: zlib,none [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: zlib,none [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: first_kex_follows 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_parse_kexinit: reserved 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: mac_setup: setup hmac-sha1 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: kex: client->server aes128-ctr hmac-sha1 none [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: mac_setup: setup hmac-sha1 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: kex: server->client aes128-ctr hmac-sha1 none [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: kex: diffie-hellman-group14-sha1 need=20 dh_need=20 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: kex: diffie-hellman-group14-sha1 need=20 dh_need=20 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: bits set: 1032/2048 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: expecting SSH2_MSG_KEXDH_INIT [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: bits set: 1044/2048 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: monitor_read: 6 used once, disabling now
Apr 21 05:04:48 lcnt sshd[11503]: debug2: kex_derive_keys [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: set_newkeys: mode 1 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SSH2_MSG_NEWKEYS sent [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: expecting SSH2_MSG_NEWKEYS [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: set_newkeys: mode 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SSH2_MSG_NEWKEYS received [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: KEX done [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: userauth-request for user root service ssh-connection method publickey [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: attempt 0 failures 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: parse_server_config: config reprocess config len 758
Apr 21 05:04:48 lcnt sshd[11503]: debug2: monitor_read: 8 used once, disabling now
Apr 21 05:04:48 lcnt sshd[11503]: debug2: input_userauth_request: setting up authctxt for root [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: input_userauth_request: try method publickey [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: test whether pkalg/pkblob are acceptable [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: PAM: initializing for "root"
Apr 21 05:04:48 lcnt sshd[11503]: debug1: PAM: setting PAM_RHOST to "192.168.206.1"
Apr 21 05:04:48 lcnt sshd[11503]: debug1: PAM: setting PAM_TTY to "ssh"
Apr 21 05:04:48 lcnt sshd[11503]: debug2: monitor_read: 100 used once, disabling now
Apr 21 05:04:48 lcnt sshd[11503]: debug2: monitor_read: 4 used once, disabling now
Apr 21 05:04:48 lcnt sshd[11503]: debug2: monitor_read: 80 used once, disabling now
Apr 21 05:04:48 lcnt sshd[11503]: debug1: temporarily_use_uid: 0/0 (e=0/0)
Apr 21 05:04:48 lcnt sshd[11503]: debug1: trying public key file /root/.ssh/authorized_keys
Apr 21 05:04:48 lcnt sshd[11503]: debug1: fd 4 clearing O_NONBLOCK
Apr 21 05:04:48 lcnt sshd[11503]: Found matching DSA key: f2:1b:ea:7f:5a:6d:d6:13:90:1a:4e:54:e4:3e:14:2a
Apr 21 05:04:48 lcnt sshd[11503]: debug1: restore_uid: 0/0
Apr 21 05:04:48 lcnt sshd[11503]: debug2: userauth_pubkey: authenticated 0 pkalg ssh-dss [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: Postponed publickey for root from 192.168.206.1 port 9304 ssh2 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: userauth-request for user root service ssh-connection method publickey [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: attempt 1 failures 0 [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: input_userauth_request: try method publickey [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: temporarily_use_uid: 0/0 (e=0/0)
Apr 21 05:04:48 lcnt sshd[11503]: debug1: trying public key file /root/.ssh/authorized_keys
Apr 21 05:04:48 lcnt sshd[11503]: debug1: fd 4 clearing O_NONBLOCK
Apr 21 05:04:48 lcnt sshd[11503]: Found matching DSA key: f2:1b:ea:7f:5a:6d:d6:13:90:1a:4e:54:e4:3e:14:2a
Apr 21 05:04:48 lcnt sshd[11503]: debug1: restore_uid: 0/0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: ssh_dss_verify: signature correct
Apr 21 05:04:48 lcnt sshd[11503]: debug1: do_pam_account: called
Apr 21 05:04:48 lcnt sshd[11503]: Accepted publickey for root from 192.168.206.1 port 9304 ssh2: DSA f2:1b:ea:7f:5a:6d:d6:13:90:1a:4e:54:e4:3e:14:2a
Apr 21 05:04:48 lcnt sshd[11503]: debug1: monitor_child_preauth: root has been authenticated by privileged process
Apr 21 05:04:48 lcnt sshd[11503]: debug2: mac_setup: setup hmac-sha1
Apr 21 05:04:48 lcnt sshd[11503]: debug2: mac_setup: setup hmac-sha1
Apr 21 05:04:48 lcnt sshd[11503]: debug2: userauth_pubkey: authenticated 1 pkalg ssh-dss [preauth]
Apr 21 05:04:48 lcnt sshd[11503]: debug1: monitor_read_log: child log fd closed
Apr 21 05:04:48 lcnt sshd[11503]: debug1: temporarily_use_uid: 0/0 (e=0/0)
Apr 21 05:04:48 lcnt sshd[11503]: debug1: ssh_gssapi_storecreds: Not a GSSAPI mechanism
Apr 21 05:04:48 lcnt sshd[11503]: debug1: restore_uid: 0/0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SELinux support enabled
Apr 21 05:04:48 lcnt sshd[11503]: debug1: PAM: establishing credentials
Apr 21 05:04:48 lcnt sshd[11503]: pam_unix(sshd:session): session opened for user root by (uid=0)
Apr 21 05:04:48 lcnt sshd[11503]: debug2: set_newkeys: mode 0
Apr 21 05:04:48 lcnt sshd[11503]: debug2: set_newkeys: mode 1
Apr 21 05:04:48 lcnt sshd[11503]: debug1: Entering interactive session for SSH2.
Apr 21 05:04:48 lcnt sshd[11503]: debug2: fd 4 setting O_NONBLOCK
Apr 21 05:04:48 lcnt sshd[11503]: debug2: fd 5 setting O_NONBLOCK
Apr 21 05:04:48 lcnt sshd[11503]: debug1: server_init_dispatch_20
Apr 21 05:04:48 lcnt sshd[11503]: debug1: server_input_channel_open: ctype session rchan 0 win 262144 max 32768
Apr 21 05:04:48 lcnt sshd[11503]: debug1: input_session_request
Apr 21 05:04:48 lcnt sshd[11503]: debug1: channel 0: new [server-session]
Apr 21 05:04:48 lcnt sshd[11503]: debug2: session_new: allocate (allocated 0 max 10)
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_new: session 0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_open: channel 0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_open: session 0: link with channel 0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: server_input_channel_open: confirm session
Apr 21 05:04:48 lcnt sshd[11503]: debug1: server_input_channel_req: channel 0 request pty-req reply 1
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_by_channel: session 0 channel 0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_input_channel_req: session 0 req pty-req
Apr 21 05:04:48 lcnt sshd[11503]: debug1: Allocating pty.
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_pty_req: session 0 alloc /dev/pts/3
Apr 21 05:04:48 lcnt sshd[11503]: debug1: SELinux support enabled
Apr 21 05:04:48 lcnt sshd[11503]: debug1: server_input_channel_req: channel 0 request x11-req reply 1
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_by_channel: session 0 channel 0
Apr 21 05:04:48 lcnt sshd[11503]: debug1: session_input_channel_req: session 0 req x11-req
Apr 21 05:04:49 lcnt sshd[11503]: debug1: server_input_channel_req: channel 0 request shell reply 1
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_by_channel: session 0 channel 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_input_channel_req: session 0 req shell
Apr 21 05:04:49 lcnt sshd[11503]: Starting session: shell on pts/3 for root from 192.168.206.1 port 9304
Apr 21 05:04:49 lcnt sshd[11503]: debug2: fd 3 setting TCP_NODELAY
Apr 21 05:04:49 lcnt sshd[11503]: debug2: channel 0: rfd 9 isatty
Apr 21 05:04:49 lcnt sshd[11503]: debug2: fd 9 setting O_NONBLOCK
Apr 21 05:04:49 lcnt sshd[11503]: debug2: channel 0: rcvd adjust 262144
Apr 21 05:04:49 lcnt sshd[11503]: debug1: server_input_channel_req: channel 0 request window-change reply 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_by_channel: session 0 channel 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_input_channel_req: session 0 req window-change
Apr 21 05:04:49 lcnt sshd[11503]: debug1: server_input_channel_req: channel 0 request window-change reply 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_by_channel: session 0 channel 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_input_channel_req: session 0 req window-change
Apr 21 05:04:49 lcnt sshd[11503]: debug1: server_input_channel_req: channel 0 request window-change reply 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_by_channel: session 0 channel 0
Apr 21 05:04:49 lcnt sshd[11503]: debug1: session_input_channel_req: session 0 req window-change

[Char]

If compression is ON and i try to get really long line in terminal 250kb+

console freezes and stops working showing no error .

its 100% repeatable on VisualGDB last version and smartty 1.1/2.2

1. turn compression is ON
2. create text file with one line and size 250+kb (i use -file-list-exec-source-files output string 600kb)
3. cat this file

if compression OFF – akk ok, when its on after 250KB it freezes.

 

[support]

Hi,

Thanks for reporting this. The compression implementation comes from the libssh2 library that VisualGDB/SmarTTY is using and we don’t really want to modify it as it could create more problems that it would solve. You can experiment with building the latest version (we use 1.6.0) from sources and replacing the DLL that comes with VisualGDB.

If the debugging is slow, most likely this is caused by the latency and not the bandwidth (unless you are debugging over a dial-up connection or something similarly slow). We would recommend using the command timing analysis button in the GDB Session window to find out which commands take the most time.

[Char]

Hi you use version 1.4.2 , can you update it ti version 1.4.3 ? i cant compile it like DLL /

Version 1.4.3 – November 27 2012

Changes:

• compression: add support for zlib@openssh.com

Bug fixes:

• comp_method_zlib_decomp: handle Z_BUF_ERROR when inflating

• This reply was modified 7 years, 12 months ago by Char.

[support]

Hi,

We are not using OpenSSH. We are using libssh2, which is a different library.

[Char]

Hi ,i know  i talk about libssh2

https://www.libssh2.org/changes.html
<div class=”subtitle” align=”left”>Version 1.4.3 – November 27 2012</div>
libssh2 1.4.3 GPG sig (685712 bytes)

<b>Changes:</b>

• compression: add support for zlib@openssh.com

<b>Bug fixes:</b>

• sftp_read: return error if a too large package arrives
• libssh2_hostkey_hash.3: update the description of return value
• Fixed MSVC NMakefile
• examples: use stderr for messages, stdout for data
• openssl: do not leak memory when handling errors
• improved handling of disabled MD5 algorithm in OpenSSL
• known_hosts: Fail when parsing unknown keys in known_hosts file
• configure: gcrypt doesn’t come with pkg-config support
• session_free: wrong variable used for keeping state
• libssh2_userauth_publickey_fromfile_ex.3: mention publickey == NULL
• comp_method_zlib_decomp: handle Z_BUF_ERROR when inflating

<div class=”subtitle” align=”left”>Version 1.4.2 – May 18 2012</div>

[support]

Hi,

VisualGDB is using the version 1.6.0 (June 12 2015) that should include that fix. If it does not work with your machine, most likely it is another bug of libssh2. We will consider updating to 1.7.0 in one of the next VisualGDB releases.

[Char]

Hi, you have wrong information latest VisualGDB-5.1.4.676 have same same lib version like SmarTTY 1.0   i compare it byte-byte 🙂

You use lib with compile date 19 november 2012  🙂 and at that date it was latest version of libssh2 🙂

[support]

Hi,

Thanks for pointing that out. It does indeed look like we shipped the old one. Please try this build: http://sysprogs.com/files/tmp/VisualGDB-5.1.4.683.msi

[Char]

Thank you very much compression works now

tail -f /var/log/secure | grep -E "zlib|compression|client"
Apr 23 00:18:14 lcnt sshd[11009]: debug1: Client protocol version 2.0; client software version libssh2_1.7.0_DEV
Apr 23 00:18:15 lcnt sshd[11009]: debug2: kex_parse_kexinit: none,zlib@openssh.com [preauth]
Apr 23 00:18:15 lcnt sshd[11009]: debug2: kex_parse_kexinit: none,zlib@openssh.com [preauth]
Apr 23 00:18:15 lcnt sshd[11009]: debug2: kex_parse_kexinit: zlib,zlib@openssh.com,none [preauth]
Apr 23 00:18:15 lcnt sshd[11009]: debug2: kex_parse_kexinit: zlib,zlib@openssh.com,none [preauth]
Apr 23 00:18:15 lcnt sshd[11009]: debug1: kex: client->server aes128-ctr hmac-sha2-256 zlib@openssh.com [preauth]
Apr 23 00:18:15 lcnt sshd[11009]: debug1: kex: server->client aes128-ctr hmac-sha2-256 zlib@openssh.com [preauth]
Apr 23 00:18:15 lcnt sshd[11009]: debug1: Enabling compression at level 6. [preauth]
Apr 23 00:18:26 lcnt sshd[11019]: debug1: Client protocol version 2.0; client software version libssh2_1.7.0_DEV
Apr 23 00:18:26 lcnt sshd[11019]: debug2: kex_parse_kexinit: none,zlib@openssh.com [preauth]
Apr 23 00:18:26 lcnt sshd[11019]: debug2: kex_parse_kexinit: none,zlib@openssh.com [preauth]
Apr 23 00:18:26 lcnt sshd[11019]: debug1: kex: client->server aes128-ctr hmac-sha2-256 none [preauth]
Apr 23 00:18:26 lcnt sshd[11019]: debug1: kex: server->client aes128-ctr hmac-sha2-256 none [preauth]

[Char]

Ohh, thank you very much!

this update makes me happy 🙂 now i have average time for command ~ 290ms per command before was ~350+ 🙂

Is is possible to batch commands  or other way to get to make debugger response more faster?

[support]

As we mentioned before, there is not a lot of difference from turning on the compression. You can close the Threads and Call Stack windows in Visual Studio, then it will query less things and the overall performance should increase.

You can also try using a cross-toolchain with gdb running on the Windows side. This may improve the performance a bit more.

• This reply was modified 7 years, 12 months ago by support.

[Char]

Thank you i ‘ ll try close this windows when i debug slow remote host.

You think compression not a big deal? heh  🙂 upload/download sourses, debug begin time (when it sends meny commands before show any window in VS)

that 60ms   290ms vs 350ms its +20%  response time.  🙂

Source upload/download time now works 4-5times  faster  🙂

One more speed hint what you don`t set out of the box –  enable multi tread compilation -j8

 

• This reply was modified 7 years, 12 months ago by Char.

[Char]

I tried it on test project  🙂

If “Threads” window open each step over command translates into 7 gdb instructions

-exec-next
 -thread-list-ids
 -thread-select 1
 -stack-list-frames
 -stack-list-arguments 0
 -stack-select-frame 0
 -thread-select 1

If i close call stack and threads  i got 4 commands  🙂 open\close call stack window not change it

-exec-next
-thread-select 1
-stack-list-frames
-stack-list-arguments 0

• This reply was modified 7 years, 12 months ago by Char.
• This reply was modified 7 years, 12 months ago by Char.

[support]

Hi,

Yes, this makes sense. Normally if you are using a newer gdb version, the -thread-select should be automatically replaced with the –thread argument passed to -stack-list-frames, so you’ll get 3 commands. If you disable the “show arguments” and other similar settings in the call stack window, you’ll get only 2 commands that is pretty much the absolute minimum.

[Author]

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