Out of Memory issue while using Lettuce 3.x

hetalh...@gmail.com

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May 8, 2019, 1:52:03 PM5/8/19

to lettuce-redis-client-users

I am using Lettuce 3.x that occasionally throws OutOfMemory errors while using LatencyUtils class. Here is the Heap dump trace.

Class Name | Shallow Heap | Retained Heap

-----------------------------------------------------------------------------------------------------

org.LatencyUtils.SimplePauseDetector @ 0x3c4e36fd0 | 80 | 3,828,661,568

|- <class> class org.LatencyUtils.SimplePauseDetector @ 0x3c4b13a28 | 24 | 24

|- highPriorityListeners java.util.ArrayList @ 0x3c4e37020 | 24 | 559,776

|- normalPriorityListeners java.util.ArrayList @ 0x3c4e37038 | 24 | 3,548,415,056

| |- <class> class java.util.ArrayList @ 0x3c0a2f790 System Class | 32 | 80

| |- elementData java.lang.Object[70803] @ 0x3d7913170 | 283,232 | 3,548,415,032

| | |- <class> class java.lang.Object[] @ 0x3c0843868 | 0 | 0

| | |- [17] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fca0e80| 32 | 113,160

| | |- [16] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fca1b10| 32 | 113,160

| | |- [15] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fca27a0| 32 | 113,160

| | |- [14] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fceba58| 32 | 113,160

| | |- [13] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fcec6e8| 32 | 113,160

| | |- [12] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fd37638| 32 | 113,160

| | |- [11] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fd382c8| 32 | 113,160

| | |- [10] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fd38f58| 32 | 113,160

| | |- [9] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fd814a8 | 32 | 113,160

| | |- [8] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fd82138 | 32 | 113,160

| | |- [7] org.LatencyUtils.LatencyStats$PauseTracker @ 0x42fdcc700 | 32 | 113,160

-----------------------------------------------------------------------------------------------------

Any leads on how to get through this issue?

Note that this happened only once and auto recovered after my service was restarted. I want to avoid the service outage in future due to this issue.

hetalh...@gmail.com

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May 8, 2019, 3:14:41 PM5/8/19

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Will upgrading Lettuce to 4.2 or further help as LatencyUtils dependency is optional as quoted in the dependency compatibility matrix: https://github.com/lettuce-io/lettuce-core/wiki/Dependency-Compatibility-Matrix?

Mark Paluch

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May 8, 2019, 6:11:40 PM5/8/19

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Lettuce 3.x is out of support for 3 years.

Please upgrade to Lettuce 5.1.6 which is the latest version. Removing LatencyUtils will no longer spin up SimplePauseDetector so you should not see any heap being occupied by it.