After quite a significant hiatus, I have just released a new version of SLAMD, which I am calling 2.0.0-20090227. It isn’t the official 2.0.0 release, but it should be pretty solid, and there are significant improvements over the previous 2.0.0-alpha1 build. You can get it at http://www.slamd.com/, and the source is hosted in a subversion repository at http://slamd2.dev.java.net/.
This is the first public build of SLAMD since I left Sun, but the SLAMD codebase hasn’t exactly been collecting dust since then. One of the first things that I did when we founded UnboundID was to start working on the UnboundID LDAP SDK for Java, and within a few weeks of that I was already using it in SLAMD jobs. However, since until recently our LDAP SDK was not publicly available, I couldn’t really release a version of SLAMD that included it, and I didn’t want to maintain a separate private version of the code that made use of the SDK and a public version that didn’t. Now that our LDAP SDK is open source and publicly available, I’m able to use it in SLAMD without any concerns.
Since it has been over two years since the last public commit, and since I had problems with an older mail server, I have recreated all of the SLAMD mailing lists without any members. If you were previously subscribed to any of the mailing lists and want to keep it that way, then you’ll need to re-subscribe to the desired lists. Instructions for doing so are available at http://www.slamd.com/mailing-lists.shtml.
Note that a number of changes have been made in this release that make it incompatible with earlier releases, and you probably won’t be able to export data from an older server and import it into this new version and have it all work seamlessly. I think that the enhancements in this version were worth it, especially if you’re using it to test LDAP directory servers, and hopefully the incompatibilities introduced now will help avoid the need to introduce further incompatibilities in the future.
Changes Since SLAMD 2.0.0-alpha1
There have been a lot of changes made to SLAMD since the 2.0.0-alpha1 release. Some of the most significant changes are outlined below. There have also been a number of less significant bugfixes and enhancements that probably aren’t worth mentioning individually.
Source Code Refactoring
The source code has been completely refactored in several ways. The code now uses a simplified package structure of “
com.slamd.*“. The “
example” sub-package has been renamed to “
jobs“. All of the source code is now in one single directory structure rather than having separate source locations for a number of the tools.
The source code has also been fully updated to use Java 5 functionality. As a result, SLAMD now requires that you use Java 5.0 or later (I recommend the latest Java 6 build). The code has been updated to use generics and builds cleanly with all lint options enabled. As a result of updating to Java 5, I have also been able to take advantage of the better concurrency support and more accurate timing that it provides.
The job API has been updated so that it is now possible to provide both long and short descriptions. Further, where it previously used the
destroy() method as a means of trying to forcefully stop a job, I have changed that to
destroyThread(), since the former method overrode the deprecated
Thread.destroy() method which I shouldn’t have done in the first place.
As mentioned above, most of the LDAP-based jobs now use the UnboundID LDAP SDK for Java. This provides better performance and scalability than the Netscape Directory SDK that I had previously been using, and it’s also much more stable under load. All of the LDAP-based jobs using the UnboundID LDAP SDK now extend a common parent class which provides a number of benefits for these jobs, including:
- It is now possible to perform client-side load balancing so that you can stress multiple servers at once with a single job.
- All of these jobs support SSL and StartTLS for secure communication with the directory server, and I’ve simplified the interface so that it’s no longer necessary to worry about key or trust stores.
- These jobs offer the ability to specify a response time threshold, which can be used to keep track of the number of times that an operation took longer than the specified length of time to complete.
I have consolidated many of the LDAP-based jobs where it made sense to do so, so that there are no longer as many jobs but you should still have the same basic set of capabilities, in addition to new features.
The LDAP Add and Delete Rate job now provides the ability to control how the operations are performed. You can choose to perform only adds, only deletes, or both adds and deletes. If you choose to perform both, then you can either have all of the adds done first and then all of the deletes, or you can choose to delete each entry immediately after adding it.
The LDAP AuthRate job now supports the ability to authenticate using the CRAM-MD5, DIGEST-MD5, or PLAIN SASL mechanisms in addition to using simple authentication.
The LDAP ModRate job allows you to specify the set of characters to use to create the modification, so it will work better with attributes that syntaxes that don’t accept arbitrary characters.
I’ve added a new LDAP Modify DN Rate job which can be used to measure modify DN performance. You can specify a range of entries to be renamed, and the job will actually rename them twice. The first time it will rename them to include the job ID in the RDN, and the second time it will rename them back to the original value.
I’ve added a new LDAP Multi-Connection SearchRate job which allows you to perform searches while maintaining large numbers of connections to the directory in order to test performance with lots of active connections.
I’ve added a new “Wait for Directory” job which allows you to wait for a directory server to become available and start accepting requests before continuing on with other jobs that need to communicate with the server.
I have gotten rid of some older jobs that hadn’t been updated in a while and that targeted outdated software or software that I wasn’t in a position to support. This primarily included the jobs targeting an ancient version of the Sun Calendar Server, old versions of the Access Manager product, and the Identity Synchronization for Windows. If this is a significant problem, then it shouldn’t be difficult to resurrect them, but I didn’t want to invest the time cleaning them up and I wasn’t in any position to test them to see if they still work properly.
Resource Monitor Updates
A new resource monitor has been provided that makes it possible to capture arbitrary information from an LDAP directory server that exposes monitoring information. This was written by Bertold Kolics and it is very useful because it can be used to collect all kinds of monitoring information about the state of the directory server while a job is running (if the directory that you’re targeting exposes the desired information).
I’ve also fixed some bugs in a couple of the resource monitors. In particular, the VMStat monitor has been updated to support newer versions of Linux, and the IOStat monitor has been updated to fix a problem where it didn’t always work properly on Solaris.
I have updated the TimeTracker so that it uses the high-resolution timer which can provide up to nanosecond-level accuracy. Previously the TimeTracker only supported millisecond-level accuracy, but this wasn’t fine-grained enough for timing things that took less than a few milliseconds to complete.
The SLAMD client and resource monitor clients have been updated so that it is now possible to explicitly specify the client ID and source IP address to use when communicating with the SLAMD server. This is particularly useful on multi-homed systems, especially when they might have multiple IP addresses on the same network.
I have updated the job scheduler so that it now uses a blocking queue that allows a new job to be seen immediately. If it’s eligible to start running at the time that it’s scheduled, then it will often be the case that the job will already be running before the administrative interface renders the page indicating that the job has been scheduled.
I have changed the layout of the tools directory so that instead of providing separate subdirectories for each of the major tools, the code for each of those tools is integrated into the main codebase and now there are just shell scripts and batch files for launching them. I have also added a new Tools Guide that summarizes the tools that are available and provides information about using them.
The UnboundID LDAP SDK for Java provides searchrate, modrate, and authrate command-line tools as example programs, and they are now exposed as tools available for use within SLAMD. They are also available through shell scripts or batch files in the tools directory.
I have made some changes to the way that statistics are displayed in the administrative interface so that they are less likely to require horizontal scrolling.
The descriptions for the available jobs have been improved, and it’s now easier to tell what a job does when you schedule it. On the page allowing you to pick which type of job to schedule, SLAMD now provides a pop-up hint that gives a short description of the job. The page allowing you to provide the parameters to use when scheduling a job has also been updated to provide a more detailed description of the job at the top of the page.