Towards PhiloLogic4

Earlier this year I wrote a long discussion paper called "Renovating PhiloLogic" which provided an overview of the system architecture, a frank review of the strengths and (many) failings of the current implementation of the 3 series of PhiloLogic, and proposed a general design model for what would effectively be a complete reimplementation of the system, retaining only selected portions of the existing code base. While we are still discussing this, often in great detail, a few general objectives for any future renovation have emerged, including:

• service oriented architecture;
• release of new system in perl module libraries;
• multiple database query support, and,
  
• options for advanced or extended indexing models.

I will be putting together a public version of this discussion draft in the near future and will blog it when I have something ready.

Before sallying forth to do start working on a PhiloLogic4, there are a number of preliminary steps that Richard and I agree are required in order to 1) support the existing PhiloLogic3 series, and 2) clear the existing (messy) code base of some of the most egregious sections of the system, most notably the loader. Some of these are simply housekeeping and updates, some of these are patches and bug fixes, and some others are clean-ups which should streamline the current system and help in any redevelopment.

We will start by retasking one of our current machines, a 32 bit OS-X installation, to be the primary PhiloLogic development machine. We will also get the Linux branch on a 32 bit Linux machine (flavor to be determined). There is a known 64 bit installation problem which we will address at the end of this initial process. When we reach the right step, we will install it all on 64 bit machines and fix it then, hopefully with much less effort on a streamlined version, while releasing upgraded 32 bit versions on the way. The other element for our consideration is the degree to which we can merge the OS-X and Linux branches of the system. Right now, we have two completely distinct branches. It would be much better to have one, which we think may be accomplished in a couple of different ways.

We are currently thinking of 4 distinct steps, which should each result in new maintenance releases of PhiloLogic3.

Step One

Apply the most recent OS-X Leopard patch kit to both the OS-X and Linux branches as required and feasible. This is the patch kit that Richard and I assembled for the migration to our new servers and has some nifty little extensions. We will also be updating the PhiloLogic code release site (Google Code) and retooling the new PhiloLogic site, which will then be referred from the existing location (philologic.uchicago.edu). Maintenance release when done. [MVO]

Step Two

The PhiloLogic loader currently using a GNU Makefile scheme to load databases. This made good sense many years ago, when loads could take many hours (or days), but is probably no longer needed. There are also many places where we use various utilities (sed, gawk, gzip, etc.) which add complications and make the entire scheme more brittle. Our current thinking is to fold all of the Makefile functions into a revised version of philoload, but may determine a better way to proceed once we get into it. We're planning a maintenance release of this when done. [MVO]

Step Three

The current PhiloLogic loader performs a number of C compiles, many of which are no longer needed. For example, the system still compiles the search2 binaries. These were left in Philologic3 in order to have backwards compatibility. We need to keep the ability to generate the correct pack and unpack libraries which are used by search3. Once we have cleared out all unnecessary C compiles, we will investigate a couple of known bugs in search3, and attempt to resolve these. Again, once done, we would do a maintenance release. [RW and MVO]

Step Four

As noted above, some users have reported 64 bit compile problem on either installation or load. Once we have the loader streamlined, eliminating as much of the old C compiles are possible, we will investigate this problem. We're hoping that this will be easily remedied and, even better, could be resolved in a combined release which would merge the current OS-X and Linux branches. This would be the terminal release of the PhiloLogic3 series. Any future releases would be only for bug fixes.

We hoping that these steps will result in a stable terminal release of the PhiloLogic3 series, which will be easier to install and use. It will also result in significant streamlining which will help in any future Philologic renovation or a new PhiloLogic4 series.

This is an initial plan, so please do post your comments, suggestions, and complaints.