I have over 500 machines distributed across a WAN covering three continents. Periodically, I need to collect text files which are on the local hard disk on each blade. Each server is running Windows server 2003 and the files are mounted on a share which can be accessed remotely as \server\Logs. Each machine holds many files which can be several Mb each and the size can be reduced by zipping.
Thus far I have tried using Powershell scripts and a simple Java application to do the copying. Both approaches take several days to collect the 500Gb or so of files. Is there a better solution which would be faster and more efficient?
I guess it depends what you do with them ... if you are going to parse them for metrics data into a database, it would be faster to have that parsing utility installed on each of those machines to parse and load into your central database at the same time.
Even if all you are doing is compressing and copying to a central location, set up those commands in a .cmd file and schedule it to run on each of the servers automatically. Then you will have distributed the work amongst all those servers, rather than forcing your one local system to do all the work. :-)
The first improvement that comes to mind is to not ship entire log files, but only the records from after the last shipment. This of course is assuming that the files are being accumulated over time and are not entirely new each time.
You could implement this in various ways: if the files have date/time stamps you can rely on, running them through a filter that removes the older records from consideration and dumps the remainder would be sufficient. If there is no such discriminator available, I would keep track of the last byte/line sent and advance to that location prior to shipping.
Either way, the goal is to only ship new content. In our own system logs are shipped via a service that replicates the logs as they are written. That required a small service that handled the log files to be written, but reduced latency in capturing logs and cut bandwidth use immensely.
Each server should probably:
manage its own log files (start new logs before uploading and delete sent logs after uploading)
name the files (or prepend metadata) so the server knows which client sent them and what period they cover
compress log files before shipping (compress + FTP + uncompress is often faster than FTP alone)
push log files to a central location (FTP is faster than SMB, the windows FTP command can be automated with "-s:scriptfile")
notify you when it cannot push its log for any reason
do all the above on a staggered schedule (to avoid overloading the central server)
Perhaps use the server's last IP octet multiplied by a constant to offset in minutes from midnight?
The central server should probably:
accept log files sent and queue them for processing
gracefully handle receiving the same log file twice (should it ignore or reprocess?)
uncompress and process the log files as necessary
delete/archive processed log files according to your retention policy
notify you when a server has not pushed its logs lately
We have a similar product on a smaller scale here. Our solution is to have the machines generating the log files push them to a NAT on a daily basis in a randomly staggered pattern. This solved a lot of the problems of a more pull-based method, including bunched-up read-write times that kept a server busy for days.
It doesn't sound like the storage servers bandwidth would be saturated, so you could pull from several clients at different locations in parallel. The main question is, what is the bottleneck that slows the whole process down?
I would do the following:
Write a program to run on each server, which will do the following:
Monitor the logs on the server
Compress them at a particular defined schedule
Pass information to the analysis server.
Write another program which sits on the core srver which does the following:
Pulls compressed files when the network/cpu is not too busy.
(This can be multi-threaded.)
This uses the information passed to it from the end computers to determine which log to get next.
Uncompress and upload to your database continuously.
This should give you a solution which provides up to date information, with a minimum of downtime.
The downside will be relatively consistent network/computer use, but tbh that is often a good thing.
It will also allow easy management of the system, to detect any problems or issues which need resolving.
NetBIOS copies are not as fast as, say, FTP. The problem is that you don't want an FTP server on each server. If you can't process the log files locally on each server, another solution is to have all the server upload the log files via FTP to a central location, which you can process from. For instance:
Set up an FTP server as a central collection point. Schedule tasks on each server to zip up the log files and FTP the archives to your central FTP server. You can write a program which automates the scheduling of the tasks remotely using a tool like schtasks.exe:
KB 814596: How to use schtasks.exe to Schedule Tasks in Windows Server 2003
You'll likely want to stagger the uploads back to the FTP server.
Related
I'm using Apache Camel to interact with several SFTP endpoints; for each one, I perform the following pipeline:
retrieve the list of existing files
validate those files against a given set of rules
download remote files, in case of successful validation
Everything works like a charm (for about a hundred different endpoints) and the URI used to retrieve the list of files is something like that: sftp://${HOST}:${PORT}/${DIR}?username=${USER}&download=false&recursive=true&disconnect=true&sendEmptyMessageWhenIdle=true
The problem is that, for one of those SFTP endpoints, the SFTP Camel component behaves, alternatively, as follows:
immediately return 0 remote files
takes a couple of minutes to list the remote content (which is composed by around 250 files, from 2KB to 2MB each)
In addition, in the latter case, the download takes around 30 seconds to download only 10KB of data.
Since this is happening on this specific SFTP only, I suppose it doesn't directly depend on Camel, which works fine for all other endpoints.
So, my questions are:
what can affect such a connection, leading to an unreasonable delay (there are no network issues, nor huge data to fetch)?
supposing it depends on the remote SFTP endpoint, why should the aforementioned Camel URI immediately return 0 files, since lots of files exist in the SFTP?
Thanks for any feedback.
Let's assume there is no bug in the Camel SFTP component of your version.
what can affect such a connection, leading to an unreasonable delay
(there are no network issues, nor huge data to fetch)?
Consider the fact that your app can immediately return 0 remote files, the problem source exist between your app and target server is relatively low. For server side, it could be
Too many folders to traverse
Server have slow action on each call
other problem on server side
For the case (Too many folders to traverse), consider to ignore folders that are useless and other config (e.g. stepwise)
supposing it depends on the remote SFTP endpoint, why should the
aforementioned Camel URI immediately return 0 files, since lots of
files exist in the SFTP?
The server side could be using multiple SFTP server nodes and some nodes are empty due to file system synchronization failure. When client is being redirect to any empty SFTP server node by server side's gateway, server node return 0 remote files in response and client report as-is.
I am working on an application where the user has the potential to download thousands of files in one request into a zip file. Obviously, this will not be practical for our server. What would be the best way to go about serving up thousands of files to users?
Right now, what I have been working on is just have the jquery fileDownload library make a request for 100 files, then in the success handler call the fileDownload again for another 100 files offset by 100. The problem with this is that the fileDownload library (or the server) waits about 20 seconds until the fileDownload fail callback is called.
The other problem with this method is it isn't practical for the client to receive hundreds of pop windows asking them if they want to download 100 files.
We also won't be able to send back thousands of files in the response because our server doesn't and won't have that much memory.
This is purely opinion based on my experience but two options i have seen in use:
Option 1:
Batch process files, compress, then advise user of download location. This should be limited number of files and size tho as it can burn out the server resources. I don't recommend this if you have large number of users.
Option 2 (Best):
Batch process files into compressed file, then either enable uses to FTP into the location to obtain the files, or if your users have FTP location, have the file transfered over to the FTP location. I can tell you definitely this is most effective and is used by number of corporations i have been invovled with.
I'm trying to upload several hundred files to 10+ different servers. I previously accomplished this using FileZilla, but I'm trying to make it go using just common command-line tools and shell scripts so that it isn't dependent on working from a particular host.
Right now I have a shell script that takes a list of servers (in ftp://user:pass#host.com format) and spawns a new background instance of 'ftp ftp://user:pass#host.com < batch.file' for each server.
This works in principle, but as soon as the connection to a given server times out/resets/gets interrupted, it breaks. While all the other transfers keep going, I have no way of resuming whichever transfer(s) have been interrupted. The only way to know if this has happened is to check each receiving server by hand. This sucks!
Right now I'm looking at wput and lftp, but these would require installation on whichever host I want to run the upload from. Any suggestions on how to accomplish this in a simpler way?
I would recommend using rsync. It's really good at only transferring just the data that's been changed during a transfer. Much more efficient than FTP! More info on how to resume interrupted connections with an example can be found here. Hope that helps!
Is there a utility for Windows that allows you to test different aspects of file transfer operations across a Lan or a Wan.
Example...
How long does it take to move a file of a known size (500 MB or 1 GB) from Server A (on site) to Server B (on site) or to Server C (off site-Satellite location)?
D-ITG will allow you to test many aspects of your links. It does not necessarily allow you transfer a file directly, but it allows you to control almost all aspects of the transmission of data across the wire.
If all you are interested in is bulk transfer time (and not all the nitty-gritty details) you could just use a basic FTP application and time the transfer.
Probably nothing you've not already figured out. You could get some coarse grain metrics using a batch file to coordinate:
start monitoring
copy file
stop monitoring
Copy file might just be initiating a file copy between two nodes on the LAN, or it might initiate a FTP copy between two nodes on the WAN.
Monitoring could be as basic as writing the current time to output or file, or it could be as complex as adding performance counter metrics from the network adapter on the two machines.
A commercial WAN emulator would also give you the information your looking for. I've used the Shunra Appliance successfully in the past. Its pretty expensive, so I'd really only recommend it if critical business success is riding on understanding how application behavior could change based on network conditions and is something you could incorporate into regular testing activities.
I have a farm of several physical servers each running a large number of Ruby "workers" (daemon-like processes) and I'd like to be able to monitor the health and progress of these processes from a central location, perhaps with historical graphing like Cacti provides. What's the simplest preferably-open-standard protocol for doing something like that? Please note I'm already using monit to keep the processes up and running and under control; what I'm asking for here is a single point of entry (i.e. dashboard) for checking in on them. Thanks.
If you are already using Monit then M/Monit sounds like a perfect match.
"M/Monit expand upon Monit's capabilities to provide monitoring and management of all Monit enabled hosts from one simple to use web-interface. " - http://mmonit.com/
G'day,
What about having a monitoring process on each server that checks the status of each process and then writes that out to a flat text file, say once every five minutes.
Then another process located on a central server can retrieve at those flat files and trawl through the results and flag any issues.
If you save the individual files and timestamp them, you would also be able to see any trends forming.
Just a quick ideea.
BTW The above system is used to monitor the servers in one of the largest websites in the world. Our scripts are written in Perl with a little bit of shell script but I don't see why you couldn't write your monitoring scripts in Ruby as well.
HTH
cheers,
I'd suggest to take a look at Zabbix.
It's not as simple as monit, of course, but it allows you to run data collecting agent on each of your servers, with all agents feeding the central reporting and storage server with their data. Those agents can use any custom scripts to get the metrics - you can write simple scripts to extract the data you need from your workers, send it back to the central reporting server and display it there on the dashboard.