Upgrading from Allegrograph 4.0m1 to Allegrograph 4.0m2
There are two main issues in upgrading AllegoGraph:
- Upgrading your data
- Upgrading your code
We cover each of these issues below in the sections below.
Upgrading Triple-stores
Triple stores created with AllegoGraph 4.0m1 cannot directly be used with AllegoGraph 4.0m2. The on-disk format has changed as follows:
- Large strings are stored in compressed form in the strings file
In order to make a triple-store created with AllegoGraph 4.0m1 usable in AllegoGraph 4.0m2, a conversion must be made to upgrade the triple-stores into the new format. This conversion can be done with the command-line convertdb.
IMPORTANT: Back up your database before you use convertdb!
As triple stores can be large, upgrading them does not create a copy of the original database before modifying the data. Instead, the data is converted in-place, which reduces the disk space requirements for the conversion process. The conversion still needs some disk space. In the worst case, a temporary copy of one of the files in the database directories is made. Thus, every directory that the database uses must have at least as much free space as the largest of the files in that directory.
Thus, before upgrading your databases, make a full backup of your database directories.
Command-line tool
The command line tool convertdb is located in bin directory of your distribution. It can be used to upgrade triple-stores into the new format. convertdb takes one command line argument:
$ convertdb db-directory The db-directory is the directory where the triple-store that you wish to convert is located.
If you execute convertdb with the wrong number of arguments, it will display brief usage information:
haldol 107_> convertdb
invalid arguments
Usage: db-directory If you provide a valid set of arguments, then it will make the conversion and provide progress information as it goes.
haldol 108_> convertdb /franz/root/twitter-m1a/
; upgrading database in /franz/root/twitter-m1a/ from version 1 to version 2
; running database upgrade step #<db-upgrade-step update-string-tables 1 -> 2>
; converting upi table file /franz/root/twitter-m1a/sstab-current-6.dat
; total 714971 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-3.dat
; total 1894851 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-2.dat
; total 3071995 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-0.dat
; total 4251033 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-6.dat
; total 5430518 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-7.dat
; total 6610125 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-1.dat
; total 7788173 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-4.dat
; total 8966980 entries converted
; converting upi table file /franz/root/twitter-m1a/sstab-merged-5-5.dat
; total 10146537 entries converted
; 10146537 strings converted
; database version upgrade complete When complete, the AllegroGraph 4.0 triple-store will be upgraded and can be used.
Important!
It is not currently possible to re-open a converted AllegroGraph 4.0m2 triple-store in AllegroGraph 4.0m1. We recommend that you make a backup of your original triple-store while you work with the new one. Please contact Franz if you need additional support working withe the new triple-store format and the conversion tools.
