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IDProjectCategoryView StatusLast Update
0006469Rocky-Linux-8Generalpublic2024-05-02 14:32
ReporterShreyans K Assigned To 
Status newResolutionopen 
Platformx86_64OSRocky LinuxOS Version8
Summary0006469: Inconsistent application RAM usage increase in Rocky Linux 8 compared to Centos 7
DescriptionI have a C++ application that basically downloads some text files over HTTP and processes them. For each file, I create a Reader object that allocates a byte array buffer of size 1 MB on initialization. For this experiment's purpose, I have disabled all processing post these object creations. I am just creating one Reader object per file. What I have observed on Rocky Linux 8 is that after creating say N number of Reader objects for N files, the application RAM usage remains constant for a while (1-2 hours) and then starts increasing at a constant rate for about a day and then stabilizes. Please note that no processing is taking place after the creation of N objects. On CentOS 7 for the same experiment, the RAM usage remains constant after initialization of N objects as expected.
I am attaching a screenshot of a graph of the app RAM usage depicting this same scenario. Note that in this, I am creating 400 Reader objects for 400 files on application start up. As can be seen, the app RAM usage remains constant at around 1 GB mark for about 1.5 hours and then starts increasing in steps of approximately 60 MB per 5 minutes. The duration of the graph is around 11 hours.
Please help in making sense of this unexplained memory increase and how I can resolve this.
Additional Information1. No parallel processes are running on the system during this experiment
2. Values of some relevant sysctl parameters are as follows (All default Rocky 8 values):
vm.dirty_background_bytes = 0
vm.dirty_background_ratio = 10
vm.dirty_bytes = 0
vm.dirty_expire_centisecs = 3000
vm.dirty_ratio = 40
vm.dirty_writeback_centisecs = 500
vm.dirtytime_expire_seconds = 43200
vm.memory_failure_early_kill = 0
vm.memory_failure_recovery = 1
vm.min_free_kbytes = 90112
vm.nr_hugepages = 0
vm.nr_hugepages_mempolicy = 0
vm.nr_overcommit_hugepages = 0
vm.numa_stat = 1
vm.overcommit_kbytes = 0
vm.overcommit_memory = 0
vm.overcommit_ratio = 50
vm.swappiness = 10
TagsNo tags attached.
Attached Files
app_ram_usage.JPG (63,392 bytes)   
app_ram_usage.JPG (63,392 bytes)   


Issue History

Date Modified Username Field Change
2024-05-02 14:32 Shreyans K New Issue
2024-05-02 14:32 Shreyans K File Added: app_ram_usage.JPG