Stack Overflow
Stack Overflow

Questions tagged [g1gc]

G1 or Garbage First is a generational partially collecting concurrent and parallel garbage collection algorithm. It is targeted for multi-processor machines with large memories and can meet soft realtime requirements with garbage collection (GC) pause time goals. An implementation of the G1 currently ships with the new Java 7 VMS - officially supported from JDK7 update 4.

G1 or "Garbage First" is a generational partially collecting concurrent and parallel garbage collection algorithm. It is targeted for multi-processor machines with large memories and can meet soft realtime requirements with garbage collection (GC) pause time goals.

An implementation of the G1 currently ships with the Java Hotspot 7 VM - officially supported from JDK7 update 4.

Resources

314 questions
2
votes
0 answers

what algorithm does the g1 GC based on to resize the Eden region

I found a GC problem in my application, young GC suddenly becomes 10 times as much as normal which result of a small size of eden region. Through the gc log, I found than eden size become 5000M-7000M usually while it keeped 528M when falled into…
zbliu
  • 21
  • 1
2
votes
1 answer

Soft Reference in the role of GC in java

Recently I come across this article which does the GC tuning the Jenkins which talks about this paramter : -XX:SoftRefLRUPolicyMSPerMB https://jenkins.io/blog/2016/11/21/gc-tuning/ I understand it prevents OOM error, Because it clears the Soft…
Harry
  • 3,072
  • 6
  • 43
  • 100
2
votes
1 answer

Why do we need a specific search for unreachable objects in Old Generation if we know all dead objects after marking them on the Young Generation?

I know that in CMS and G1 heap is divided into Eden, Survivor spaces and Old Generation with only difference that in CMS this division is real (these spaces are contiguous and located in different parts of memory) and in G1 it is logical (the heap…
user5536368
2
votes
2 answers

Cassandra and G1 Garbage collector stop the world event (STW)

We have a 6 node Cassandra Cluster under heavy utilization. We have been dealing a lot with garbage collector stop the world event, which can take up to 50 seconds in our nodes, in the meantime Cassandra Node is unresponsive, not even accepting new…
Scudeler
  • 91
  • 1
  • 7
2
votes
2 answers

when will be G1 ( Garbage Collector) starts running and in which memory area it collect first ? what are the new GC update on java 8?

when will be G1 ( Garbage Collector) starts running and in which memory area it collect first? what is the new GC update on java 8?
B_Ali
  • 74
  • 1
  • 2
  • 10
2
votes
1 answer

G1 GC — extremely long termination time

G1 GC sometimes spends a lot of time in termination phase. As you can see while GC worker average time is 442.9 termination is 327.3. That is high performance low latency application that processes a lot of messages. Event processing data must be…
Pavel Moukhataev
  • 149
  • 1
  • 10
2
votes
0 answers

Java G1 occupy more memory?

Is there have a limit for G1,some article mentioned the max region size is 32M,and max regions num is 2K,so it seem the max heap size is 64GB. But in our cluster,it's work well when the heap is 106GB: Garbage-First (G1) GC with 18 thread(s) Heap…
hellodengfei
  • 21
  • 2
2
votes
1 answer

Prevent JVM from releasing heap back to OS when using G1 collector

I want to use the latest G1 garbage collector however I am running into a situation where I hit memory allocation errors when using it. I believe this is because it is releasing memory back to the OS, and the OS is then not allowing the JVM to have…
Casey Jordan
  • 1,204
  • 1
  • 20
  • 39
2
votes
1 answer

G1 Collector not doing full GC

For a week after switching to java 1.7.0_80, observed this behavior S0C S1C S0U S1U EC EU OC OU PC PU YGC YGCT FGC FGCT GCT 0 32M 0 32M 512M 128M 9.5G 7.7G 640M 475M 26487 157min 0 0min 157min No Full GC, large space…
Sameer Naik
  • 1,326
  • 1
  • 13
  • 28
2
votes
1 answer

Releasing memory back to OS when JVM is idle

We have a simple microservice setup, based on Spring Boot and Java 8 on Windows servers. Many of the services have a low load, since they serve as integrations to all kinds of external partners. So they are idle a lot of the time. The problem is…
Lasse L
  • 1,278
  • 1
  • 9
  • 14
2
votes
2 answers

infrequent long GC pauses with G1GC

I am experiencing infrequent long GC pauses with G1GC algorithm - 30+ seconds for a month. Once it happens, I restart my service and this delay won't happen again for next 1 month. I am attaching GC log. 2016-06-15T02:30:17.407-0400: 1702455.276:…
Ravindra babu
  • 37,698
  • 11
  • 250
  • 211
2
votes
1 answer

Which JVM Flag sets the GC overhead threshold mentioned in the G1Ergonomics log?

I'm using the G1 garbage collector. You can enable adaptive size policy logs with -XX:+PrintAdaptiveSizePolicy Here's sample output in the GC logs 1822.780: [G1Ergonomics (Heap Sizing) attempt heap expansion, reason: recent GC overhead higher…
Savior
  • 3,225
  • 4
  • 24
  • 48
2
votes
1 answer

G1GC: How to use all free memory?

I try to use G1GC with my program. Program is used on various machines with various memory size: VPS with 1Gb memory (minimum), desktop with 8Gb memory, DS with 32Gb memory (maximum). I noticed that G1GC not reserve more memory even if there is a…
Xupypr MV
  • 935
  • 10
  • 18
2
votes
2 answers

How do I get G1 to print more log details?

I'm testing a Jetty-based API vs a Netty-based one. With the only difference in the experiment being which API I use (same application, same servers, same memory config, same load etc. etc.), I get longer GC pauses with the Netty-based one. Mostly,…
Jacob Davis-Hansson
  • 2,603
  • 20
  • 26
2
votes
1 answer

G1 slower than default garbage collector on Java 7

I have been trying to use G1 on my applications, and noticed it takes more time to start an application compared to default garbage collector on java 7u91. On the other hand, less collections were execute as G1 is supposed to be. Is there any…
Carlos Alberto
  • 7,761
  • 13
  • 52
  • 72
1 2 3
…
20 21