unable to start rstudio in centos getting error "unable to connect to service"

Question

I have Rstudio server installed on CentOS 6, but I cannot login to Rstudio from the browser at http://localhost:8787 in browser. A popup titled "RStudio Initialization Error" appears with message "Unable to connect to service".

I have tried the following to remedy the error, but I have been without success:

$ sudo rstudio-server verify-installation
rstudio-server stop/waiting
rserver[19273]: ERROR system error 13 (Permission denied) [username=rstudio-server]; OCCURRED AT: core::Error server::launchSession(const std::string&, const core::system::Options&, PidType*) /root/rstudio/src/cpp/server/ServerSessionManager.cpp:223; LOGGED FROM: int main(int, char* const*) /root/rstudio/src/cpp/server/ServerMain.cpp:428
rstudio-server start/running, process 19287

$ id -u supstat1
502 (user name is more than 500)

$ sudo usermod -g rstudio_users supstat1

$ sudo vi /etc/sysconfig/iptables as root
and added the following line(s)
Add -A INPUT -m state --state NEW -m tcp -p tcp --dport 8787 -j ACCEPT
Add -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

$ sudo lsof | grep rstudio
rserver   9597 rstudio-server  cwd       DIR                8,1      4096          2 /
rserver   9597 rstudio-server  rtd       DIR                8,1      4096          2 /
rserver   9597 rstudio-server  txt       REG                8,1   7990044     553699 /usr/lib/rstudio-server/bin/rserver
rserver   9597 rstudio-server  mem       REG                8,1    156928     391944 /lib64/ld-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1   1926800     391948 /lib64/libc-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1    599384     396110 /lib64/libm-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1     22536     391993 /lib64/libdl-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1    145896     391952 /lib64/libpthread-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1     91096     391950 /lib64/libz.so.1.2.3
rserver   9597 rstudio-server  mem       REG                8,1   1410824     564111 /usr/lib64/libcrypto.so.0.9.8e
rserver   9597 rstudio-server  mem       REG                8,1    327488     567429 /usr/lib64/libssl.so.0.9.8e
rserver   9597 rstudio-server  mem       REG                8,1    124624     396127 /lib64/libselinux.so.1
rserver   9597 rstudio-server  mem       REG                8,1    113952     406171 /lib64/libresolv-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1     18936     396128 /lib64/libuuid.so.1.3.0
rserver   9597 rstudio-server  mem       REG                8,1     93320     396113 /lib64/libgcc_s-4.4.7-20120601.so.1
rserver   9597 rstudio-server  mem       REG                8,1     17256     392157 /lib64/libcom_err.so.2.1
rserver   9597 rstudio-server  mem       REG                8,1    177520     392161 /lib64/libk5crypto.so.3.1
rserver   9597 rstudio-server  mem       REG                8,1     12592     406310 /lib64/libkeyutils.so.1.3
rserver   9597 rstudio-server  mem       REG                8,1    280520     392159 /lib64/libgssapi_krb5.so.2.2
rserver   9597 rstudio-server  mem       REG                8,1    944712     391997 /lib64/libkrb5.so.3.3
rserver   9597 rstudio-server  mem       REG                8,1    989840     536152 /usr/lib64/libstdc++.so.6.0.13
rserver   9597 rstudio-server  mem       REG                8,1     46368     406311 /lib64/libkrb5support.so.0.1
rserver   9597 rstudio-server  mem       REG                8,1     17520     406322 /lib64/libutil-2.12.so
rserver   9597 rstudio-server  mem       REG                8,1     65928     391959 /lib64/libnss_files-2.12.so
rserver   9597 rstudio-server    0u      CHR                1,3       0t0       3643 /dev/null
rserver   9597 rstudio-server    1u      CHR                1,3       0t0       3643 /dev/null
rserver   9597 rstudio-server    2u      CHR                1,3       0t0       3643 /dev/null
rserver   9597 rstudio-server    3r     FIFO                0,8       0t0      37905 pipe
rserver   9597 rstudio-server    4w     FIFO                0,8       0t0      37905 pipe
rserver   9597 rstudio-server    5u      REG                0,9         0       3641 anon_inode
rserver   9597 rstudio-server    6u     IPv4              37907       0t0        TCP *:msgsrvr (LISTEN)

Answer 1

When you login the rserver process handles your authentication, and then fires up an rsession process, which is the session you will use. The problem occurs when the rsession process terminates due to an error.

If you have administrator privileges, you can debug the error by tracing the rserver process and looking at the problem that caused rsession to exit. Here is how to do it.

First find the rserver process-id.

ps auxw | grep studio
rstudio-server       7035  0.0  0.0 362488  4480 ?        Ssl  16:37   0:01 /usr/local/lib/rstudio-server/bin/rserver

Note the second number that appears on the output of a row containing the string rstudio-server/bin/rserver. In the case above the process-id is 7035.

Then trace rserver sending the output to a file. The number after -p should be the rserver process-id. The funky -e option is used to cut-down noise from Java's thread management.

sudo strace -f -e 'trace=!clock_gettime,gettimeofday,futex,timerfd_settime,epoll_wait,epoll_ctl' -p 7035 -o trace.txt

Login and wait for the error message to appear.

Stop the tracing by pressing ctrl-c.

Open the file with your favourite editor, and search for the string exit_group.

The lines above it are likely to indicate the error in rsession. In my case it was a symbolic link from .rstudio to a missing directory.

7529  mkdir("/home/dds/.rstudio", 0777) = -1 EEXIST (File exists)
7529  stat("/home/dds/.rstudio", 0x7ffff37419b0) = -1 ENOENT (No such file or directory)
7529  write(2, "07 Feb 2015 16:46:53 [rsession-d"..., 395) = 395
7529  sendto(3, "<11>Feb  7 16:46:53 rsession-dds"..., 398, MSG_NOSIGNAL, NULL, 0) = 398
7529  exit_group(1)