ELOG Forum

Re: Invalid Content-Length in header when running behind a load balancer

3.1.4-3

I have the same problem. I found a temporary solution: https://elog.psi.ch/elogs/Forum/69807

Tamas Gal wrote:

I put the ELOG service behind an Apache reverse proxy which is now sitting behind the HAProxy. It works like this, but it's just a workaround. I am pretty sure that ELOG has problems to communicate with HAProxy correctly and it seems that Apache is more forgiving. So that the chain HAProxy -> Apache -> ELOG and vice versa is working.

If anyone manages to figure out what's wrong, I am happy to get rid of the extra reverse proxy layer!

Tamas Gal wrote:

I am still struggling to get ELOG running behind a load balancer and hope to get some advice here. As already reported in https://elog.psi.ch/elogs/Forum/69542 I observed an infinite loop of redirects when prompted to log in and using a non-empty password file. Without a password, the service worked as expected. This was with version 3.1.3.

With the new version 3.1.4-3, I get another error: "Invalid Content-Length in header" when I click on "submit" of a new post. Viewing the logbooks works fine. The instance is currently live and running here: https://elog.test.km3net.de but I might change it anytime due to debugging etc.

This is a kind of difficult thing to debug (I spent the whole day and no progress). The only thing I've found was this post: https://techcommunity.microsoft.com/t5/iis-support-blog/invalid-content-length/ba-p/3038724 where it seems that some responses are not RFC conform and were rejected in the load-balancer.

The load balancer I use is HAProxy, the same as in my old setup where I got the infinite redirects, and I can't find any setting which would work. To my understanding, the most basic setup should work just fine. The SSL termination is on the load-balancer side so ELOG doesn't even have to know anything about it. The configuration is below. I am running a single instance, so there is not even replication with session keep-alive via cookies or anything fancy.

I also want to mention that I am runnin around 30 different services behind the load balancer and none of them are having any issues with the SSL termination or the load-balancing itself, that's why assume that something in ELOG is either non-conform or buggy.

Any thoughts? I'd really like to use the same infrastructure for the ELOG service as for every other service (automatic certificate renewal via letsencrypt, load-balancing, easy movement to other nodes, SSL termination etc.), to minimise the complexity of our Docker Swarm system.

backend be_elog.km3net.de mode http server-template km3net-elog- 1 km3net-elog_elog:8080 check resolvers docker init-addr libc,none

Btw. I am running ELOG with -v but I don't see any error whatsoever in the logs:

km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | GET /demo/ HTTP/1.1
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "ios_specific_templates_id"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "rl_anonymous_id"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "rl_group_id"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "rl_group_trait"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "rl_trait"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "rl_user_id"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Received unknown cookie "logged_out_marketing_header_id"
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Returned 3437 bytes
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | GET / HTTP/1.1
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Returned 120 bytes
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | GET /demo/ HTTP/1.1
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Returned 3518 bytes
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | GET / HTTP/1.1
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Returned 120 bytes
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | GET /demo/ HTTP/1.1
km3net-elog_elog.1.fm8i1eia9l9t@ecap-s021 | Returned 3518 bytes

904

Mon Feb 7 09:58:25 2005

Question

repository of elog configuration files


Hi 

Is there a repository of elog configuration files for newbies to lookup and
learn ? I have seen the 'contributions' elog - useful as it is ... it is not
much. I would appreciate if someone can point out such a site where people
have contributed their elog configuration files.

Thanks,
AnandO.

929

Fri Feb 11 15:44:38 2005

Question

Help with configuration newbie

Hi,

We have set up a elog server at our institute. The configuration file is
attached. We have the following queries:

1. When replying to another reply in a thread, the author_name attribute is
not substitued (as desired). Since this is a mandatory field, we are not
able to send the reply message. However, reply to the originial message
works fine.

2. "Use Email From = string" prepends an additional "" to the "From"
field in the e-mails.

3. "Fixed Attributes Reply = Subject" fixes the subject line while replying.
However when we add "Category" attribute to this list, it breaks.

Can someone help us?

Suggestions and tips will be thankfully recieved.

Attachment 1: elog_config.txt

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;  CMB ELOG CONFIGURATION  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

password file = cmb.pwd
Admin User = sarah, sengupta
Self register = 3
Menu commands = New, Edit, Reply, Find, Config, Admin, Change password, Download, Logout, Help
Find Menu commands = New, Edit, Reply, Find, Config, Admin, Change password, Logout, Help
Theme = default
Comment = Extended Hierarchical Search Pipeline Development

; -- A few flags
Page Title = ELOG - $subject
Reverse sort = 1
Quick filter = Date, Type
LogFile = /usr/local/epd.log
Filtered browsing = 0
Summary lines = 0
Resubmit default = 2
Restrict edit = 1

; -- Default mode for search display. On the find entry form, the checkboxes are set accordingly.
Display mode = threaded

; -- Number of logbook entries displayed per page in a search result. The default is 20.
Entries per page = 25

; -- Define a number of attributes for the logbook, separated by commata. Typical values are "Author", 
; -- "Subject" or  "Type".
Attributes = Author, Category, Subject
ROptions Category = General, Reference, Methods, Results, Query
Required Attributes = Author, Subject, Category

; -- preset author and email attributes
Preset Author = $long_name
Preset Author Email = $user_email

; -- add last revision on each edit
Subst on Edit Last Revision = $date by $long_name

; -- these attributes cannot be changed ever
Locked Attributes = Author, Last Revision

; -- We don't want a default email message to go to all the users
Suppress email to users = 0
Display Email recipients = 0
Use Email Subject = [ELOG] $subject
Use Email From = "$long_name <$user_email>"

; -- Options for edit (Author and email is already preset so we dont need to substitute those attributes)
Subst on edit subject  = $subject (revised)
Subst on edit category = $category

; -- The attributes specified here cannot be modified during Editing
Fixed Attributes Edit = Author, Author Email, Subject

; -- Options for reply (Anyone can reply so we must remove Author and email attributes from reply and substitute the 
; -- current logged in person's name and email id) 
Subst on reply subject = Re: $subject
Subst on reply category = $category
Subst on reply Author  = $long_name
Subst on reply Email = $user_email
Remove on reply = Author, Author Email

; -- The attributes specified here cannot be modified when an existing entry is modified via the Reply button
Fixed Attributes Reply = Subject

938

Sat Feb 12 20:51:43 2005

Question

Re: Help with configuration newbie

> > 1. When replying to another reply in a thread, the author_name attribute is
> > not substitued (as desired). Since this is a mandatory field, we are not
> > able to send the reply message. However, reply to the originial message
> > works fine.
> 
> Preset on reply Author = $long_name
> 
> Do not use "Remove on reply".

This worked. Thanks.

> 
> > 2. "Use Email From = string" prepends an additional "" to the "From"
> > field in the e-mails.
> 
> This has been fixed recently, please update.

Agani, thanks for the information.

> 
> > 3. "Fixed Attributes Reply = Subject" fixes the subject line while replying.
> > However when we add "Category" attribute to this list, it breaks.
> 
> I tried to use your config file and add
> 
> Fixed attributes reply = Subject, Category
> 
> and it worked as expected. What kind of "break" did you observe?

For me, when I put the Category in the fixed attributes for reply, I see the
Category but when I actually try to send the message - it says Category not
entered. I am sure I am doing something very stupid. Please help.

- Anand.

951

Fri Feb 18 08:43:42 2005