Issue #19524 has been updated by ufuk (Ufuk Kayserilioglu). In your code example you keep adding strings to an array named `an_array` which has to hold a reference to all those strings. Of course they will not be garbage collected, since they are not garbage, they are live. Imagine if after your `loop ... end` you were to write the code `puts an_array[50]`, what would you expect to happen? If all the array elements were garbage collected, Ruby would not be able to find any entry at offset `50`, but I don't think that's anyones expectation. ---------------------------------------- Bug #19524: Garbage Collector is not working as expected. https://bugs.ruby-lang.org/issues/19524#change-102314 * Author: hjimenez89rb (Hugo Alberto Jiménez Santos) * Status: Open * Priority: Normal * ruby -v: 3.1.2 * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- We are currently developing a Ruby based web application which connects to a DB2 Database . WE have been using ibm_db-5.4.0 to establish a connection. We are currently following the IBM and Ruby documentation but the application crashes by garbage collector Ruby error. We have checked the issue with IBM_team to make sure that It was not a IBM_GEM problem but as a result of their tests, IBM_GEM is working in different cases but for us we face up with those errors even with those versions (2.7.6, 3.1.2, 3.2.1): */usr/local/rvm/gems/ruby-3.2.1/gems/ibm_db-5.4.0/lib/active_record/connection_adapters/ibm_db_adapter.rb:3104: warning: undefining the allocator of T_DATA class IBM_DB::Statement /usr/local/rvm/rubies/ruby-3.2.1/lib/ruby/3.2.0/rubygems/specification.rb:1048: [BUG] object allocation during garbage collection phase *0x0/usr/local/rvm/gems/ruby-3.1.2/gems/ibm_db-5.4.0/lib/active_record/connection_adapters/ibm_db_adapter.rb:760: [BUG] object allocation during garbage collection phase ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux] *Exception occurred on Step thread ID #SID:34117;RSEQ:911723; wrong instance allocation; backtrace: /usr/local/rvm/gems/ruby-3.1.2/gems/ibm_db-5.4.0/lib/active_record/connection_adapters/ibm_db_adapter.rb:760:in `server_info' (RuntimeError) /usr/local/rvm/gems/ruby-3.1.2/gems/ibm_db-5.4.0/lib/active_record/connection_adapters/ibm_db_adapter.rb:760:in `initialize'. (all trace is attached in this ticket) OS name: "CentOS" version: "8" architecture: "x86_64" rvm: version: "1.29.12 (latest)" As an extra error, we're not sure if Warning! PATH is not properly set up, /usr/local/rvm/gems/ruby-3.2.1/bin is not at first place. Usually this is caused by shell initialization files. Search for PATH=... entries. You can also re-add RVM to your profile by running: rvm get stable --auto-dotfiles To fix it temporarily in this shell session run: rvm use ruby-3.2.1 To ignore this error add rvm_silence_path_mismatch_check_flag=1 to your ~/.rvmrc file. Garbage collector leack test this code we have been running manually garbage collector, if you can see in this example:T_STRING. is not deceasing the stings in live memory, Even executig GC manualy. (log is attached) GC.disable # Only run GC when manually called an_array = [] loop do 1000.times { an_array << "A" + "B" + "C" } puts "Array is #{an_array.size} items long" GC.start # Run a major GC - use full_mark: false for minor GC pp ObjectSpace.count_objects sleep 1 end ---Files-------------------------------- LOGS3.txt (12.5 KB) LOGS4.txt (127 KB) LOGS2.txt (9.62 KB) LOGS1.txt (123 KB) leacky.txt (3.64 KB) -- https://bugs.ruby-lang.org/