From: Luke Kanies Date: 2006-04-14T04:51:21+09:00 Subject: Managing memory consumption Hi all, I've got a framework [1] that transfers files either locally or over XML::RPC. In either case, memory consumption is significantly higher than I would think it should be, but in the case of XML::RPC it's so high that I can't actually test it on VMWare images because they don't have enough RAM (and I don't have enough RAM to allocate all of them enough RAM). Is there anything I can do to force deallocation of memory when I know I'm done with it? I'm confident it's not a memory leak on my part because memory usage levels off after the first full iteration (well, I know it levels off if I don't use XML::RPC, but I get failures with it so I can't test that), even if I recreate all of the objects from scratch on each loop (and I'm not using any class variables or globals or anything). The application, in this case, supports two methods: Send a file and receive a checksum in return, or send a checksum and receive a file in return. Here's a basic plot of what my memory consumption looks like when copying my vim binary around (it's about 3.5 MB): Start the test method: 16124K Make a copy of the file: 18604K In the 'send' method on the client: Read the file in the 'send' method: 19388K Bas64 encode the file: 27708K In the 'send' method on the server: Base64 decode the file: 31020K Read in the server-side file for comparison: 34284K After this point, no matter how many times I run this loop, memory never grows or shrinks. I've tried setting variables to "" to encourage memory shrinkage, but (unsurprisingly) this doesn't help. If I add XML::RPC into the mix (with the same file and the same basic process), the 'call' method in xmlrpc/client grows the memory from 28124K to 76132K in one huge jump (between the encode/decode steps). In looking at the code, it's obvious why it's happening -- the data is being copied multiple times. Still, I can't have this system using up 76MB of RAM for every type of XML::RPC client I have in memory, and if I send a larger file than 3.5MB the RAM usage climbs multiplicatively. Again, this is for one file, and this is just one part of my application. This is also a long-running application, so it's important that its average memory usage be as low as possible. At no point do I see memory usage decrease, even if I send 4 smaller files after my relatively large one. So, is there anything I can do to mitigate RAM usage here? Anything I can tell Ruby that will make it let go of that RAM? I've tried adding GC.start at the beginning and end of all of these methods, and it does not appear to make any kind of difference (which I suppose is a good thing), but I'm at a loss as to how to proceed. Any ideas? 1 - http://reductivelabs.com/projects/puppet -- The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us. --Calvin and Hobbes (Bill Watterson) --------------------------------------------------------------------- Luke Kanies | http://reductivelabs.com | http://madstop.com