Auth failed error when opening files using XRootD in pyROOT

ROOT
1

Hi,

I am trying to read a tree with TChain from lxplus and using xrootd.

This is what I do:

kinit eballabe@CERN.CH

with klist I get:

Issued Expires Principal
Apr 5 05:49:42 2024 Apr 6 06:49:41 2024 krbtgt/CERN.CH@CERN.CH
Apr 5 07:33:10 2024 Apr 6 06:49:41 2024 xrootd/eoshome.cern.ch@CERN.CH

I am able to open it with xrootd and to see its content in this way

root -l -e ‘TFile::Open(“root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root” )’
new TBrowser()

However, when I run my pyROOT code it gives me one error. In my code, what I do is:

from ROOT import TChain
chain = TChain( ‘data22’)
chain.Add(‘root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root’ )
chain.Project(“data_hist”,“met”,“1”)

which gives me this error

Error in TNetXNGFile::Open: [FATAL] Auth failed: Could not load authentication handler.

However, if I download it locally, it works

chain = TChain( ‘data22’)
chain.Add( ‘/Users/ericballabene/data22_merged_processed.root’ )
1
chain.Project(“data_hist”,“met”,“1”)
241366

Best,
Eric

ROOT Version: 6.30.06
Platform: MacOS 14.4.1

2

Hi Eric,

Thanks for the post.
This is not expected. I would like to ask you to perform a few tests to gather a more complete view of what is happening:

  1. Is the ROOT used via Python the same you are using in C++? (ROOT.gROOT.GetVersion())
  2. Can you build the same chain from C++?
  3. Could you set the environment variable ROOTDEBUG=1 (or 2 or higher) and go through the messages to see whether the logs reveal some issue with the authentication?

Best,
D

3

Hi Danilo,

as far as I can tell it’s a problem happening only with python.

Python 3.9.6 (default, Feb 3 2024, 15:58:27)
[Clang 15.0.0 (clang-1500.3.9.4)] on darwin
Type “help”, “copyright”, “credits” or “license” for more information.

import ROOT
ROOT.gROOT.GetVersion()

‘6.30/06’

  1. I built this macro.C,

#include <TChain.h>
#include <TFile.h>
#include <TH1F.h>
int main() {
TChain *chain = new TChain(“data22”);
chain->Add(“root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root”);
TH1F *data_hist = new TH1F(“data_hist”, “MET Histogram”, 100, 0, 1000);
chain->Project(“data_hist”, “met”, “1”);
TFile *outputFile = new TFile(“output.root”, “RECREATE”);
data_hist->Write();
outputFile->Close();
delete chain;
delete data_hist;
return 0;
}

this works nicely with

root -l
.L macro.C
main()

and it gives me the output tree with the histogram without errors.

A python equivalent, macro.py,

from ROOT import TChain, TFile, TH1F
def main():
chain = TChain(“data22”)
chain.Add(“root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root”)
data_hist = TH1F(“data_hist”, “MET Histogram”, 100, 0, 1000)
chain.Project(“data_hist”, “met”, “1”)
outputFile = TFile(“output.root”, “RECREATE”)
data_hist.Write()
outputFile.Close()
if name == “main”:
#main(sys.argv)
main()

when I do

python3 main.py

gives me

Error in TNetXNGFile::Open: [FATAL] Auth failed: Could not load authentication handler.

  1. I have setup ROOTDEBUG=1 or ROOTDEBUG=2 in my terminal before doing

python3 main.py

but this does not change the output.

Cheers,
Eric

4

Hi Eric,
Thanks for following up.
About ROOTDEBUG, either you export the variable or you prepend it to the invocation:

export ROOTDEBUG=2
python3 main.py

or

ROOTDEBUG=2 python3 main.py

The output will be interesting.

Cheers,
D

5

Right, I missed the export before ROOTDEBUG=2.

Here’s the log
log.out.txt (200.7 KB)

Cheers,
Eric

6

Thanks,

What is the difference between that log and the same obtained in C++? Perhaps the krb token not found or similar issues?

Best,
D

7

In python

Info in TInterpreter::TCling::AutoParse: Trying to autoparse for __cling_Un1Qu332
Info in TInterpreter::TCling::AutoParse: Starting autoparse for __cling_Un1Qu332

in c++

Info in TInterpreter::TCling::AutoParse: Trying to autoparse for __cling_Un1Qu36
Info in TInterpreter::TCling::AutoParse: Starting autoparse for __cling_Un1Qu36

and similar.

In python

Info in TInterpreter::TCling::AutoParse: Trying to autoparse for __cf_13
Info in TInterpreter::TCling::AutoParse: Starting autoparse for __cf_13

in c++

Info in TInterpreter::TCling::AutoParse: Trying to autoparse for __cf_1
Info in TInterpreter::TCling::AutoParse: Starting autoparse for __cf_1.

In python

Error in TNetXNGFile::Open: [FATAL] Auth failed: Could not load authentication handler.
Info in TInterpreter::TCling::AutoParse: Trying to autoparse for TMessageHandler
Info in TInterpreter::TCling::AutoParse: Starting autoparse for TMessageHandler

in c++

Info in TNetXNGFile::ReadBuffer: offset: 0 length: 300
Info in TNetXNGFile::ReadBuffer: [SUCCESS] bytes read: 300
Info in TNetXNGFile::ReadBuffer: offset: 100 length: 202
Info in TNetXNGFile::ReadBuffer: [SUCCESS] bytes read: 202
Info in TNetXNGFile::ReadBuffer: offset: 19058178 length: 137
Info in TNetXNGFile::ReadBuffer: [SUCCESS] bytes read: 137
TKey Reading 137 bytes at address 19058178.

No mention of the krb token or similar

Cheers,
Eric

8

Did you try with higher verbosity levels? Does the same happen from a lxplus node?

9

I haven’t tried with other verbosity levels. python code works on lxplus.

10

Possibly this was already reported here

11

I have also tried

import ROOT
f = ROOT.TFile.Open(‘root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root’)

and this gives me

Error in TNetXNGFile::Open: [FATAL] Auth failed: Could not load authentication handler.

So I think it’s a problem of XRootD accessing eos files with pyROOT (nothing to do with TChain in particular) and I’m wondering if that happens only to me or it is a general pyROOT issue

Cheers,
Eric

12

@amadio Any ideas?

13

Since the code works on lxplus, it is not too likely that this is a generic PyROOT issue, right?
It would be interesting after increasing the verbosity to see whether indications are present about why the authentication process is not working on your system.
But indeed @amadio is the right expert to comment about this issue.

Best,
Danilo

14

Yes, it works on lxplus but also XRootD is not needed to access eos files on lxplus.
I increased the verbosity with

export XRD_LOGLEVEL=“Debug”

and got

import ROOT
f = ROOT.TFile.Open(‘root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root’)

[2024-04-08 15:50:59.846238 +0200][Debug ][Utility ] Initializing xrootd client version: v5.5.2
[2024-04-08 15:50:59.846474 +0200][Warning][Utility ] Unable to process global config file: [ERROR] OS Error: no such file or directory
[2024-04-08 15:50:59.846490 +0200][Debug ][Utility ] Unable to process user config file: [ERROR] OS Error: no such file or directory
[2024-04-08 15:50:59.846821 +0200][Debug ][PlugInMgr ] Initializing plug-in manager…
[2024-04-08 15:50:59.846826 +0200][Debug ][PlugInMgr ] No default plug-in, loading plug-in configs…
[2024-04-08 15:50:59.846838 +0200][Debug ][PlugInMgr ] Processing plug-in definitions in /etc/xrootd/client.plugins.d…
[2024-04-08 15:50:59.846848 +0200][Debug ][PlugInMgr ] Unable to process directory /etc/xrootd/client.plugins.d: [ERROR] OS Error: no such file or directory
[2024-04-08 15:50:59.846851 +0200][Debug ][PlugInMgr ] Processing plug-in definitions in /Users/ericballabene/.xrootd/client.plugins.d…
[2024-04-08 15:50:59.846855 +0200][Debug ][PlugInMgr ] Unable to process directory /Users/ericballabene/.xrootd/client.plugins.d: [ERROR] OS Error: no such file or directory
[2024-04-08 15:50:59.846858 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSeckrb5.so
[2024-04-08 15:50:59.847104 +0200][Error ][Utility ] Unable to pre-load libXrdSeckrb5.so: Plugin unable to load libXrdSeckrb5-5.so; dlopen(libXrdSeckrb5-5.so, 0x0100): tried: ‘libXrdSeckrb5-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSeckrb5-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSeckrb5-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSeckrb5-5.so’ (no such file), ‘/usr/lib/libXrdSeckrb5-5.so’ (no such file, not in dyld cache), ‘libXrdSeckrb5-5.so’ (no such file)
[2024-04-08 15:50:59.847115 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSecgsi.so
[2024-04-08 15:50:59.847259 +0200][Error ][Utility ] Unable to pre-load libXrdSecgsi.so: Plugin unable to load libXrdSecgsi-5.so; dlopen(libXrdSecgsi-5.so, 0x0100): tried: ‘libXrdSecgsi-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSecgsi-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecgsi-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecgsi-5.so’ (no such file), ‘/usr/lib/libXrdSecgsi-5.so’ (no such file, not in dyld cache), ‘libXrdSecgsi-5.so’ (no such file)
[2024-04-08 15:50:59.847265 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSecgsiAuthzVO.so
[2024-04-08 15:50:59.847408 +0200][Error ][Utility ] Unable to pre-load libXrdSecgsiAuthzVO.so: Plugin unable to load libXrdSecgsiAuthzVO-5.so; dlopen(libXrdSecgsiAuthzVO-5.so, 0x0100): tried: ‘libXrdSecgsiAuthzVO-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSecgsiAuthzVO-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecgsiAuthzVO-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecgsiAuthzVO-5.so’ (no such file), ‘/usr/lib/libXrdSecgsiAuthzVO-5.so’ (no such file, not in dyld cache), ‘libXrdSecgsiAuthzVO-5.so’ (no such file)
[2024-04-08 15:50:59.847414 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSecgsiGMAPDN.so
[2024-04-08 15:50:59.847551 +0200][Error ][Utility ] Unable to pre-load libXrdSecgsiGMAPDN.so: Plugin unable to load libXrdSecgsiGMAPDN-5.so; dlopen(libXrdSecgsiGMAPDN-5.so, 0x0100): tried: ‘libXrdSecgsiGMAPDN-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSecgsiGMAPDN-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecgsiGMAPDN-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecgsiGMAPDN-5.so’ (no such file), ‘/usr/lib/libXrdSecgsiGMAPDN-5.so’ (no such file, not in dyld cache), ‘libXrdSecgsiGMAPDN-5.so’ (no such file)
[2024-04-08 15:50:59.847557 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSecpwd.so
[2024-04-08 15:50:59.847692 +0200][Error ][Utility ] Unable to pre-load libXrdSecpwd.so: Plugin unable to load libXrdSecpwd-5.so; dlopen(libXrdSecpwd-5.so, 0x0100): tried: ‘libXrdSecpwd-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSecpwd-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecpwd-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecpwd-5.so’ (no such file), ‘/usr/lib/libXrdSecpwd-5.so’ (no such file, not in dyld cache), ‘libXrdSecpwd-5.so’ (no such file)
[2024-04-08 15:50:59.847697 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSecsss.so
[2024-04-08 15:50:59.847827 +0200][Error ][Utility ] Unable to pre-load libXrdSecsss.so: Plugin unable to load libXrdSecsss-5.so; dlopen(libXrdSecsss-5.so, 0x0100): tried: ‘libXrdSecsss-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSecsss-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecsss-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecsss-5.so’ (no such file), ‘/usr/lib/libXrdSecsss-5.so’ (no such file, not in dyld cache), ‘libXrdSecsss-5.so’ (no such file)
[2024-04-08 15:50:59.847832 +0200][Debug ][Utility ] Attempting to pre-load: libXrdSecunix.so
[2024-04-08 15:50:59.847968 +0200][Error ][Utility ] Unable to pre-load libXrdSecunix.so: Plugin unable to load libXrdSecunix-5.so; dlopen(libXrdSecunix-5.so, 0x0100): tried: ‘libXrdSecunix-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSecunix-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecunix-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSecunix-5.so’ (no such file), ‘/usr/lib/libXrdSecunix-5.so’ (no such file, not in dyld cache), ‘libXrdSecunix-5.so’ (no such file)
[2024-04-08 15:50:59.921124 +0200][Debug ][Utility ] Env: overriding entry: multiprotocol=0 with 1
[2024-04-08 15:50:59.921189 +0200][Debug ][File ] [0x3ef71fa8@root://eosuser.cern.ch:1094//eos/user/e/eballabe/merged/data22_merged_processed.root?xrdcl.requuid=D1BCB790-E8AC-403E-8573-B16A6B40A979] Sending an open command
[2024-04-08 15:50:59.921219 +0200][Debug ][Utility ] Env: trying to get a non-existent string entry: pollerpreference
[2024-04-08 15:50:59.921223 +0200][Debug ][Poller ] Available pollers: built-in
[2024-04-08 15:50:59.921225 +0200][Debug ][Poller ] Attempting to create a poller according to preference: built-in
[2024-04-08 15:50:59.921228 +0200][Debug ][Poller ] Creating poller: built-in
[2024-04-08 15:50:59.921231 +0200][Debug ][Poller ] Creating and starting the built-in poller…
[2024-04-08 15:50:59.921290 +0200][Debug ][Poller ] Using 1 poller threads
[2024-04-08 15:50:59.921294 +0200][Debug ][TaskMgr ] Starting the task manager…
[2024-04-08 15:50:59.921306 +0200][Debug ][TaskMgr ] Task manager started
[2024-04-08 15:50:59.921309 +0200][Debug ][JobMgr ] Starting the job manager…
[2024-04-08 15:50:59.921330 +0200][Debug ][JobMgr ] Job manager started, 3 workers
[2024-04-08 15:50:59.921334 +0200][Debug ][TaskMgr ] Registering task: “FileTimer task” to be run at: [2024-04-08 15:50:59 +0200]
[2024-04-08 15:50:59.921350 +0200][Debug ][ExDbgMsg ] [eosuser.cern.ch:1094] MsgHandler created: 0x3ef77c30 (message: kXR_open (file: /eos/user/e/eballabe/merged/data22_merged_processed.root, mode: 00, flags: kXR_open_read kXR_async kXR_retstat ) ).
[2024-04-08 15:50:59.921361 +0200][Debug ][PostMaster ] Creating new channel to: root://eosuser.cern.ch:1094/
[2024-04-08 15:50:59.921398 +0200][Debug ][PostMaster ] [eosuser.cern.ch:1094] Stream parameters: Network Stack: IPAuto, Connection Window: 120, ConnectionRetry: 5, Stream Error Window: 1800
[2024-04-08 15:50:59.921404 +0200][Debug ][TaskMgr ] Registering task: “TickGeneratorTask for: root://eosuser.cern.ch:1094/” to be run at: [2024-04-08 15:51:14 +0200]
[2024-04-08 15:50:59.928057 +0200][Debug ][PostMaster ] [eosuser.cern.ch:1094] Found 1 address(es): [::ffff:188.184.103.122]:1094
[2024-04-08 15:50:59.928079 +0200][Debug ][AsyncSock ] [eosuser.cern.ch:1094.0] Attempting connection to [::ffff:188.184.103.122]:1094
[2024-04-08 15:50:59.928152 +0200][Debug ][Poller ] Adding socket 0x2c64a00 to the poller
[2024-04-08 15:50:59.934317 +0200][Debug ][AsyncSock ] [eosuser.cern.ch:1094.0] Async connection call returned
[2024-04-08 15:50:59.934328 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] Sending out the initial hand shake + kXR_protocol
[2024-04-08 15:50:59.938765 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] Got the server hand shake response (type: server , protocol version 511)
[2024-04-08 15:50:59.940064 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] kXR_protocol successful (type: server , protocol version 511)
[2024-04-08 15:50:59.941786 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] Sending out kXR_login request, username: ericball, cgi: xrd.cc=ch&xrd.tz=1&xrd.appname=Python&xrd.info=&xrd.hostname=ericmacbook.dyndns.cern.ch&xrd.rn=v5.5.2, dual-stack: true, private IPv4: false, private IPv6: false
[2024-04-08 15:50:59.945573 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] Logged in, session: 7a11b8018c5800001f1a00005ce1b901
[2024-04-08 15:50:59.945580 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] Authentication is required: &P=krb5,xrootd/eoshome.cern.ch@CERN.CH&P=gsi,v:10600,c:ssl,ca:5168735f.0|4339b4bc.0&P=unix&P=sss,0.+13:/etc/eos.keytab
[2024-04-08 15:50:59.945584 +0200][Debug ][XRootDTransport ] [eosuser.cern.ch:1094.0] Sending authentication data
[2024-04-08 15:50:59.946045 +0200][Error ][XRootDTransport ] Unable to get the security framework: Plugin dlopen(libXrdSec-5.so, 0x0100): tried: ‘libXrdSec-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OSlibXrdSec-5.so’ (no such file), ‘/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSec-5.so’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/Users/sftnight/ROOT-CI/build/builtins/xrootd/XROOTD-prefix/lib/libXrdSec-5.so’ (no such file), ‘/usr/lib/libXrdSec-5.so’ (no such file, not in dyld cache), ‘libXrdSec-5.so’ (no such file) seclib libXrdSec-5.so
[2024-04-08 15:50:59.949743 +0200][Error ][AsyncSock ] [eosuser.cern.ch:1094.0] Socket error while handshaking: [FATAL] Auth failed
[2024-04-08 15:50:59.949751 +0200][Debug ][AsyncSock ] [eosuser.cern.ch:1094.0] Closing the socket
[2024-04-08 15:50:59.949755 +0200][Debug ][Poller ] <[::ffff:194.12.146.127]:56206><–><[::ffff:188.184.103.122]:1094> Removing socket from the poller
[2024-04-08 15:50:59.949787 +0200][Error ][PostMaster ] [eosuser.cern.ch:1094] elapsed = 0, pConnectionWindow = 120 seconds.
[2024-04-08 15:50:59.949796 +0200][Error ][PostMaster ] [eosuser.cern.ch:1094] Unable to recover: [FATAL] Auth failed.
[2024-04-08 15:50:59.949800 +0200][Error ][XRootD ] [eosuser.cern.ch:1094] Impossible to send message kXR_open (file: /eos/user/e/eballabe/merged/data22_merged_processed.root, mode: 00, flags: kXR_open_read kXR_async kXR_retstat ). Trying to recover.
[2024-04-08 15:50:59.949804 +0200][Debug ][XRootD ] [eosuser.cern.ch:1094] Handling error while processing kXR_open (file: /eos/user/e/eballabe/merged/data22_merged_processed.root, mode: 00, flags: kXR_open_read kXR_async kXR_retstat ): [FATAL] Auth failed.
[2024-04-08 15:50:59.949808 +0200][Debug ][ExDbgMsg ] [eosuser.cern.ch:1094] Passing to the thread-pool MsgHandler: 0x3ef77c30 (message: kXR_open (file: /eos/user/e/eballabe/merged/data22_merged_processed.root, mode: 00, flags: kXR_open_read kXR_async kXR_retstat ) ).
[2024-04-08 15:50:59.949831 +0200][Debug ][ExDbgMsg ] [eosuser.cern.ch:1094] Calling MsgHandler: 0x3ef77c30 (message: kXR_open (file: /eos/user/e/eballabe/merged/data22_merged_processed.root, mode: 00, flags: kXR_open_read kXR_async kXR_retstat ) ) with status: [FATAL] Auth failed.
[2024-04-08 15:50:59.949888 +0200][Debug ][File ] [0x3ef71fa8@root://eosuser.cern.ch:1094//eos/user/e/eballabe/merged/data22_merged_processed.root?xrdcl.requuid=D1BCB790-E8AC-403E-8573-B16A6B40A979] Open has returned with status [FATAL] Auth failed: Could not load authentication handler.
[2024-04-08 15:50:59.949894 +0200][Debug ][File ] [0x3ef71fa8@root://eosuser.cern.ch:1094//eos/user/e/eballabe/merged/data22_merged_processed.root?xrdcl.requuid=D1BCB790-E8AC-403E-8573-B16A6B40A979] Error while opening at eosuser.cern.ch:1094: [FATAL] Auth failed: Could not load authentication handler.
[2024-04-08 15:50:59.949899 +0200][Debug ][Utility ] Monitor library name not set. No monitoring
[2024-04-08 15:50:59.949905 +0200][Debug ][ExDbgMsg ] [eosuser.cern.ch:1094] Destroying MsgHandler: 0x3ef77c30.
Error in TNetXNGFile::Open: [FATAL] Auth failed: Could not load authentication handler.
Traceback (most recent call last):
File “”, line 1, in
File “/Applications/root_v6.30.06/lib/ROOT/_pythonization/_tfile.py”, line 103, in _TFileOpen
raise OSError(‘Failed to open file {}’.format(str(args[0])))
OSError: Failed to open file root://eosuser.cern.ch://eos/user/e/eballabe/merged/data22_merged_processed.root
2024-04-08 15:51:00.149 Python[87676:3983700] WARNING: Secure coding is automatically enabled for restorable state! However, not on all supported macOS versions of this application. Opt-in to secure coding explicitly by implementing NSApplicationDelegate.applicationSupportsSecureRestorableState:.

My ROOT version is 6.30.06 binary (to avoid compiling it).

15

Dear @eballabe ,

Thanks for reaching out on the forum!

XRootD is not needed to access eos files on lxplus.

I am not sure what you mean here. You do need xrootd to read files such as root://eos.../mypath/myfile.root if you are on lxplus. Maybe you mean that you can use the POSIX interface a-la /eos/user/..../myfile.root because EOS is mounted, but that in general is discouraged for performance and stability reasons.

This and similar errors are probably the real cause, somehow ROOT cannot load the correct XRootD plugins (and somehow only when running within a Python session). I guess if you repeat the same test with TFile::Open from the ROOT prompt you don’t see the same errors, right?

Meanwhile, I will try to reproduce your situation on a Mac machine and report back.

Cheers,
Vincenzo

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