Re: RE: RE: [EXTERNAL] Cluster is unbalanced
8 GiB 256 57.5% 7aca9a36-823f-4185-be44- > c1464a799084 RAC1 > > UN x 51.47 GiB 256 63.4% 18cff010-9b83-4cf8-9dc2- > f05ac63df402 RAC1 > > Datacenter: dc2 > > > > Status=Up/Down > > |/ State=Normal/Leaving/Joining/ Moving > > -- Address Load Tokens Owns (effective) Host ID > Rack > > UN 24.37 GiB 256 59.5% 1b694180-210a-4b75-8f2a- > 748f4a5b6a3d RAC1 > > UN x 30.76 GiB 256 56.7% 597bac04-c57a-4487-8924- > 72e171e45514 RAC1 > > UN 10.73 GiB 256 63.9% 6e7e474e-e292-4433-afd4- > 372d30e0f3e1 RAC1 > > UN xx 19.77 GiB 256 61.5% 58751418-7b76-40f7-8b8f- > a5bf8fe7d9a2 RAC1 > > UN x 10.33 GiB 256 58.4% 6d58d006-2095-449c-8c67- > 50e8cbdfe7a7 RAC1 > > > cassandra-rackdc.properties: > > dc=dc1 > rack=RAC1 --> same in all nodes > > cassandra.yaml: > num_tokens: 256 > > endpoint_snitch: GossipingPropertyFileSnitch > I can see cassandra-topology.properties, I believe it shouldn't be there > with GossipPropertyFileSnitch. Can this file be causing any trouble in data > distribution. > > cat /opt/cassandra/conf/cassandra- topology.properties > > # Licensed to the Apache Software Foundation (ASF) under one > > # or more contributor license agreements. See the NOTICE file > > # distributed with this work for additional information > > # regarding copyright ownership. The ASF licenses this file > > # to you under the Apache License, Version 2.0 (the > > # "License"); you may not use this file except in compliance > > # with the License. You may obtain a copy of the License at > > # > > # http://www.apache.org/ licenses/LICENSE-2.0 > <http://www.apache.org/licenses/LICENSE-2.0> > > # > > # Unless required by applicable law or agreed to in writing, software > > # distributed under the License is distributed on an "AS IS" BASIS, > > # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > > # See the License for the specific language governing permissions and > > # limitations under the License. > > > # Cassandra Node IP=Data Center:Rack > > 192.168.1.100=DC1:RAC1 > > 192.168.2.200=DC2:RAC2 > > > 10.0.0.10=DC1:RAC1 > > 10.0.0.11=DC1:RAC1 > > 10.0.0.12=DC1:RAC2 > > > 10.20.114.10=DC2:RAC1 > > 10.20.114.11=DC2:RAC1 > > > 10.21.119.13=DC3:RAC1 > > 10.21.119.10=DC3:RAC1 > > > 10.0.0.13=DC1:RAC2 > > 10.21.119.14=DC3:RAC2 > > 10.20.114.15=DC2:RAC2 > > > # default for unknown nodes > > default=DC1:r1 > > > # Native IPv6 is supported, however you must escape the colon in the IPv6 > Address > > # Also be sure to comment out JVM_OPTS="$JVM_OPTS > -Djava.net.preferIPv4Stack= true" > > # in cassandra-env.sh > > fe80\:0\:0\:0\:202\:b3ff\: fe1e\:8329=DC1:RAC3 > > > > > On Tuesday, June 19, 2018, 12:51:34 PM EDT, Durity, Sean R < > sean_r_dur...@homedepot.com> wrote: > > > You are correct that the cluster decides where data goes (based on the > hash of the partition key). However, if you choose a “bad” partition key, > you may not get good distribution of the data, because the hash is > deterministic (it always goes to the same nodes/replicas). For example, if > you have a partition key of a datetime, it is possible that there is more > data written for a certain time period – thus a larger partition and an > imbalance across the cluster. Choosing a “good” partition key is one of the > most important decisions for a Cassandra table. > > > > Also, I have seen the use of racks in the topology cause an imbalance in > the “first” node of the rack. > > > > To help you more, we would need the create table statement(s) for your > keyspace and the topology of the cluster (like with nodetool status). > > > > > > Sean Durity > > *From:* learner dba > *Sent:* Tuesday, June 19, 2018 9:50 AM > *To:* user@cassandra.apache.org > *Subject:* Re: RE: [EXTERNAL] Cluster is unbalanced > > > > We do not chose the node where partition will go. I thought it is snitch's > role to chose replica nodes. Even the partition size does not vary on our > largest column family: > > Percentile SSTables Write Latency Read LatencyPartition Size > Cell Count > > (micros) (micros) (bytes) > > > 50% 0.00 17.08 61.21
Re: RE: RE: [EXTERNAL] Cluster is unbalanced
work for additional information # regarding copyright ownership. The ASF licenses this file # to you under the Apache License, Version 2.0 (the # "License"); you may not use this file except in compliance # with the License. You may obtain a copy of the License at # # http://www.apache.org/ licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # Cassandra Node IP=Data Center:Rack 192.168.1.100=DC1:RAC1 192.168.2.200=DC2:RAC2 10.0.0.10=DC1:RAC1 10.0.0.11=DC1:RAC1 10.0.0.12=DC1:RAC2 10.20.114.10=DC2:RAC1 10.20.114.11=DC2:RAC1 10.21.119.13=DC3:RAC1 10.21.119.10=DC3:RAC1 10.0.0.13=DC1:RAC2 10.21.119.14=DC3:RAC2 10.20.114.15=DC2:RAC2 # default for unknown nodes default=DC1:r1 # Native IPv6 is supported, however you must escape the colon in the IPv6 Address # Also be sure to comment out JVM_OPTS="$JVM_OPTS -Djava.net.preferIPv4Stack= true" # in cassandra-env.sh fe80\:0\:0\:0\:202\:b3ff\: fe1e\:8329=DC1:RAC3 On Tuesday, June 19, 2018, 12:51:34 PM EDT, Durity, Sean R wrote: You are correct that the cluster decides where data goes (based on the hash of the partition key). However, if you choose a “bad” partition key, you may not get good distribution of the data, because the hash is deterministic (it always goes to the same nodes/replicas). For example, if you have a partition key of a datetime, it is possible that there is more data written for a certain time period – thus a larger partition and an imbalance across the cluster. Choosing a “good” partition key is one of the most important decisions for a Cassandra table. Also, I have seen the use of racks in the topology cause an imbalance in the “first” node of the rack. To help you more, we would need the create table statement(s) for your keyspace and the topology of the cluster (like with nodetool status). Sean Durity From: learner dba Sent: Tuesday, June 19, 2018 9:50 AM To: user@cassandra.apache.org Subject: Re: RE: [EXTERNAL] Cluster is unbalanced We do not chose the node where partition will go. I thought it is snitch's role to chose replica nodes. Even the partition size does not vary on our largest column family: Percentile SSTables Write Latency Read Latency Partition Size Cell Count (micros) (micros) (bytes) 50% 0.00 17.08 61.21 3311 1 75% 0.00 20.50 88.15 3973 1 95% 0.00 35.43 105.78 3973 1 98% 0.00 42.51 126.93 3973 1 99% 0.00 51.01 126.93 3973 1 Min 0.00 3.97 17.09 61 Max 0.00 73.46 126.93 11864 1 We are kinda stuck here to identify, what could be causing this un-balance. On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith wrote: >If it was partition key issue, we would see similar number of partition keys >across nodes. If we look closely number of keys across nodes vary a lot. I'm not sure about that, is it possible you're writing more new partitions to some nodes even though each node owns the same number of tokens? On Mon, Jun 18, 2018 at 6:07 PM, learner dba wrote: Hi Sean, Are you using any rack aware topology? --> we are using gossip file Are you using any rack aware topology? --> we are using gossip file What are your partition keys? --> Partition key is uniq Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? --> No, we verified it. If it was partition key issue, we would see similar number of partition keys across nodes. If we look closely number of keys across nodes vary a lot. Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R wrote: Are you using any rack aware topology? What are your partition keys? Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distrib
Re: RE: RE: [EXTERNAL] Cluster is unbalanced
s required by applicable law or agreed to in writing, software > > # distributed under the License is distributed on an "AS IS" BASIS, > > # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > > # See the License for the specific language governing permissions and > > # limitations under the License. > > > # Cassandra Node IP=Data Center:Rack > > 192.168.1.100=DC1:RAC1 > > 192.168.2.200=DC2:RAC2 > > > 10.0.0.10=DC1:RAC1 > > 10.0.0.11=DC1:RAC1 > > 10.0.0.12=DC1:RAC2 > > > 10.20.114.10=DC2:RAC1 > > 10.20.114.11=DC2:RAC1 > > > 10.21.119.13=DC3:RAC1 > > 10.21.119.10=DC3:RAC1 > > > 10.0.0.13=DC1:RAC2 > > 10.21.119.14=DC3:RAC2 > > 10.20.114.15=DC2:RAC2 > > > # default for unknown nodes > > default=DC1:r1 > > > # Native IPv6 is supported, however you must escape the colon in the IPv6 > Address > > # Also be sure to comment out JVM_OPTS="$JVM_OPTS > -Djava.net.preferIPv4Stack= true" > > # in cassandra-env.sh > > fe80\:0\:0\:0\:202\:b3ff\: fe1e\:8329=DC1:RAC3 > > > > > On Tuesday, June 19, 2018, 12:51:34 PM EDT, Durity, Sean R < > sean_r_dur...@homedepot.com> wrote: > > > You are correct that the cluster decides where data goes (based on the > hash of the partition key). However, if you choose a “bad” partition key, > you may not get good distribution of the data, because the hash is > deterministic (it always goes to the same nodes/replicas). For example, if > you have a partition key of a datetime, it is possible that there is more > data written for a certain time period – thus a larger partition and an > imbalance across the cluster. Choosing a “good” partition key is one of the > most important decisions for a Cassandra table. > > > > Also, I have seen the use of racks in the topology cause an imbalance in > the “first” node of the rack. > > > > To help you more, we would need the create table statement(s) for your > keyspace and the topology of the cluster (like with nodetool status). > > > > > > Sean Durity > > *From:* learner dba > *Sent:* Tuesday, June 19, 2018 9:50 AM > *To:* user@cassandra.apache.org > *Subject:* Re: RE: [EXTERNAL] Cluster is unbalanced > > > > We do not chose the node where partition will go. I thought it is snitch's > role to chose replica nodes. Even the partition size does not vary on our > largest column family: > > Percentile SSTables Write Latency Read LatencyPartition Size > Cell Count > > (micros) (micros) (bytes) > > > 50% 0.00 17.08 61.21 3311 > 1 > > 75% 0.00 20.50 88.15 3973 > 1 > > 95% 0.00 35.43105.78 3973 > 1 > > 98% 0.00 42.51126.93 3973 > 1 > > 99% 0.00 51.01126.93 3973 > 1 > > Min 0.00 3.97 17.0961 > > > Max 0.00 73.46126.93 11864 > 1 > > > > We are kinda stuck here to identify, what could be causing this un-balance. > > > > On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith < > jgalbra...@newrelic.com. INVALID> wrote: > > > > > > >If it was partition key issue, we would see similar number of partition > keys across nodes. If we look closely number of keys across nodes vary a > lot. > > I'm not sure about that, is it possible you're writing more new partitions > to some nodes even though each node owns the same number of tokens? > > [image: Image removed by sender.] > > > > On Mon, Jun 18, 2018 at 6:07 PM, learner dba invalid > wrote: > > Hi Sean, > > > > Are you using any rack aware topology? --> we are using gossip file > > Are you using any rack aware topology? --> we are using gossip file > > What are your partition keys? --> Partition key is uniq > > Is it possible that your partition keys do not divide up as cleanly as you > would like across the cluster because the data is not evenly distributed > (by partition key)? --> No, we verified it. > > > > If it was partition key issue, we would see similar number of partition > keys across nodes. If we look closely number of keys across nodes vary a > lot. > > > > > > Number of partitions (estimate): 3142552
Re: RE: RE: [EXTERNAL] Cluster is unbalanced
ion key is one of the most important decisions for a Cassandra table. Also, I have seen the use of racks in the topology cause an imbalance in the “first” node of the rack. To help you more, we would need the create table statement(s) for your keyspace and the topology of the cluster (like with nodetool status). Sean Durity From: learner dba Sent: Tuesday, June 19, 2018 9:50 AM To: user@cassandra.apache.org Subject: Re: RE: [EXTERNAL] Cluster is unbalanced We do not chose the node where partition will go. I thought it is snitch's role to chose replica nodes. Even the partition size does not vary on our largest column family: Percentile SSTables Write Latency Read Latency Partition Size Cell Count (micros) (micros) (bytes) 50% 0.00 17.08 61.21 3311 1 75% 0.00 20.50 88.15 3973 1 95% 0.00 35.43 105.78 3973 1 98% 0.00 42.51 126.93 3973 1 99% 0.00 51.01 126.93 3973 1 Min 0.00 3.97 17.09 61 Max 0.00 73.46 126.93 11864 1 We are kinda stuck here to identify, what could be causing this un-balance. On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith wrote: >If it was partition key issue, we would see similar number of partition keys >across nodes. If we look closely number of keys across nodes vary a lot. I'm not sure about that, is it possible you're writing more new partitions to some nodes even though each node owns the same number of tokens? On Mon, Jun 18, 2018 at 6:07 PM, learner dba wrote: Hi Sean, Are you using any rack aware topology? --> we are using gossip file Are you using any rack aware topology? --> we are using gossip file What are your partition keys? --> Partition key is uniq Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? --> No, we verified it. If it was partition key issue, we would see similar number of partition keys across nodes. If we look closely number of keys across nodes vary a lot. Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R wrote: Are you using any rack aware topology? What are your partition keys? Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? Sean Durity lord of the (C*) rings (Staff Systems Engineer – Cassandra) MTC 2250 #cassandra - for the latest news and updates From: learner dba Sent: Monday, June 18, 2018 2:06 PM To: User cassandra.apache.org Subject: [EXTERNAL] Cluster is unbalanced Hi, Data volume varies a lot in our two DC cluster: Load Tokens Owns 20.01 GiB 256 ? 65.32 GiB 256 ? 60.09 GiB 256 ? 46.95 GiB 256 ? 50.73 GiB 256 ? kaiprodv2 = /Leaving/Joining/Moving Load Tokens Owns 25.19 GiB 256 ? 30.26 GiB 256 ? 9.82 GiB 256 ? 20.54 GiB 256 ? 9.7 GiB 256 ? I ran clearsnapshot, garbagecollect and cleanup, but it increased the size on heavier nodes instead of decreasing. Based on nodetool cfstats, I can see partition keys on each node varies a lot: Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 How can I diagnose this imbalance further? -- Joshua Galbraith | Senior Software Engineer | New Relic C: 907-209-1208 | jgalbraith@ newrelic.com -- Joshua Galbraith | Senior Software Engineer | New Relic
Re: RE: RE: [EXTERNAL] Cluster is unbalanced
@homedepot.com> wrote: > > > You are correct that the cluster decides where data goes (based on the > hash of the partition key). However, if you choose a “bad” partition key, > you may not get good distribution of the data, because the hash is > deterministic (it always goes to the same nodes/replicas). For example, if > you have a partition key of a datetime, it is possible that there is more > data written for a certain time period – thus a larger partition and an > imbalance across the cluster. Choosing a “good” partition key is one of the > most important decisions for a Cassandra table. > > > > Also, I have seen the use of racks in the topology cause an imbalance in > the “first” node of the rack. > > > > To help you more, we would need the create table statement(s) for your > keyspace and the topology of the cluster (like with nodetool status). > > > > > > Sean Durity > > *From:* learner dba > *Sent:* Tuesday, June 19, 2018 9:50 AM > *To:* user@cassandra.apache.org > *Subject:* Re: RE: [EXTERNAL] Cluster is unbalanced > > > > We do not chose the node where partition will go. I thought it is snitch's > role to chose replica nodes. Even the partition size does not vary on our > largest column family: > > Percentile SSTables Write Latency Read LatencyPartition Size > Cell Count > > (micros) (micros) (bytes) > > > 50% 0.00 17.08 61.21 3311 > 1 > > 75% 0.00 20.50 88.15 3973 > 1 > > 95% 0.00 35.43105.78 3973 > 1 > > 98% 0.00 42.51126.93 3973 > 1 > > 99% 0.00 51.01126.93 3973 > 1 > > Min 0.00 3.97 17.0961 > > > Max 0.00 73.46126.93 11864 > 1 > > > > We are kinda stuck here to identify, what could be causing this un-balance. > > > > On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith < > jgalbra...@newrelic.com.INVALID> wrote: > > > > > > >If it was partition key issue, we would see similar number of partition > keys across nodes. If we look closely number of keys across nodes vary a > lot. > > I'm not sure about that, is it possible you're writing more new partitions > to some nodes even though each node owns the same number of tokens? > > [image: Image removed by sender.] > > > > On Mon, Jun 18, 2018 at 6:07 PM, learner dba invalid> wrote: > > Hi Sean, > > > > Are you using any rack aware topology? --> we are using gossip file > > Are you using any rack aware topology? --> we are using gossip file > > What are your partition keys? --> Partition key is uniq > > Is it possible that your partition keys do not divide up as cleanly as you > would like across the cluster because the data is not evenly distributed > (by partition key)? --> No, we verified it. > > > > If it was partition key issue, we would see similar number of partition > keys across nodes. If we look closely number of keys across nodes vary a > lot. > > > > > > Number of partitions (estimate): 3142552 > > Number of partitions (estimate): 15625442 > > Number of partitions (estimate): 15244021 > > Number of partitions (estimate): 9592992 > > Number of partitions (estimate): 15839280 > > > > > > > > > > > > On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R < > sean_r_dur...@homedepot.com> wrote: > > > > > > Are you using any rack aware topology? What are your partition keys? Is it > possible that your partition keys do not divide up as cleanly as you would > like across the cluster because the data is not evenly distributed (by > partition key)? > > > > > > Sean Durity > > lord of the (C*) rings (Staff Systems Engineer – Cassandra) > > MTC 2250 > > #cassandra - for the latest news and updates > > > > *From:* learner dba > *Sent:* Monday, June 18, 2018 2:06 PM > *To:* User cassandra.apache.org > <https://urldefense.proofpoint.com/v2/url?u=http-3A__cassandra.apache.org=DwMFaQ=MtgQEAMQGqekjTjiAhkudQ=aC_gxC6z_4f9GLlbWiKzHm1vucZTtVYWDDvyLkh8IaQ=8q4p6nWedWQJ9gpXCnoa6KR4HRmSf3B1whdYKNFub6M=TmzIaVextVyZy81p9JuU7R6PFv84RfhgtEezCe063V0=> > > *Subject:* [EXTERNAL] Cluster is unbalanced > > > > H
Re: RE: RE: [EXTERNAL] Cluster is unbalanced
y, June 19, 2018 9:50 AM To: user@cassandra.apache.org Subject: Re: RE: [EXTERNAL] Cluster is unbalanced We do not chose the node where partition will go. I thought it is snitch's role to chose replica nodes. Even the partition size does not vary on our largest column family: Percentile SSTables Write Latency Read Latency Partition Size Cell Count (micros) (micros) (bytes) 50% 0.00 17.08 61.21 3311 1 75% 0.00 20.50 88.15 3973 1 95% 0.00 35.43 105.78 3973 1 98% 0.00 42.51 126.93 3973 1 99% 0.00 51.01 126.93 3973 1 Min 0.00 3.97 17.09 61 Max 0.00 73.46 126.93 11864 1 We are kinda stuck here to identify, what could be causing this un-balance. On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith wrote: >If it was partition key issue, we would see similar number of partition keys >across nodes. If we look closely number of keys across nodes vary a lot. I'm not sure about that, is it possible you're writing more new partitions to some nodes even though each node owns the same number of tokens? On Mon, Jun 18, 2018 at 6:07 PM, learner dba wrote: Hi Sean, Are you using any rack aware topology? --> we are using gossip file Are you using any rack aware topology? --> we are using gossip file What are your partition keys? --> Partition key is uniq Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? --> No, we verified it. If it was partition key issue, we would see similar number of partition keys across nodes. If we look closely number of keys across nodes vary a lot. Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R wrote: Are you using any rack aware topology? What are your partition keys? Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? Sean Durity lord of the (C*) rings (Staff Systems Engineer – Cassandra) MTC 2250 #cassandra - for the latest news and updates From: learner dba Sent: Monday, June 18, 2018 2:06 PM To: User cassandra.apache.org Subject: [EXTERNAL] Cluster is unbalanced Hi, Data volume varies a lot in our two DC cluster: Load Tokens Owns 20.01 GiB 256 ? 65.32 GiB 256 ? 60.09 GiB 256 ? 46.95 GiB 256 ? 50.73 GiB 256 ? kaiprodv2 = /Leaving/Joining/Moving Load Tokens Owns 25.19 GiB 256 ? 30.26 GiB 256 ? 9.82 GiB 256 ? 20.54 GiB 256 ? 9.7 GiB 256 ? I ran clearsnapshot, garbagecollect and cleanup, but it increased the size on heavier nodes instead of decreasing. Based on nodetool cfstats, I can see partition keys on each node varies a lot: Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 How can I diagnose this imbalance further? -- Joshua Galbraith | Senior Software Engineer | New Relic C: 907-209-1208 | jgalbra...@newrelic.com
RE: RE: [EXTERNAL] Cluster is unbalanced
You are correct that the cluster decides where data goes (based on the hash of the partition key). However, if you choose a “bad” partition key, you may not get good distribution of the data, because the hash is deterministic (it always goes to the same nodes/replicas). For example, if you have a partition key of a datetime, it is possible that there is more data written for a certain time period – thus a larger partition and an imbalance across the cluster. Choosing a “good” partition key is one of the most important decisions for a Cassandra table. Also, I have seen the use of racks in the topology cause an imbalance in the “first” node of the rack. To help you more, we would need the create table statement(s) for your keyspace and the topology of the cluster (like with nodetool status). Sean Durity From: learner dba Sent: Tuesday, June 19, 2018 9:50 AM To: user@cassandra.apache.org Subject: Re: RE: [EXTERNAL] Cluster is unbalanced We do not chose the node where partition will go. I thought it is snitch's role to chose replica nodes. Even the partition size does not vary on our largest column family: Percentile SSTables Write Latency Read LatencyPartition Size Cell Count (micros) (micros) (bytes) 50% 0.00 17.08 61.21 3311 1 75% 0.00 20.50 88.15 3973 1 95% 0.00 35.43105.78 3973 1 98% 0.00 42.51126.93 3973 1 99% 0.00 51.01126.93 3973 1 Min 0.00 3.97 17.0961 Max 0.00 73.46126.93 11864 1 We are kinda stuck here to identify, what could be causing this un-balance. On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith wrote: >If it was partition key issue, we would see similar number of partition keys >across nodes. If we look closely number of keys across nodes vary a lot. I'm not sure about that, is it possible you're writing more new partitions to some nodes even though each node owns the same number of tokens? [Image removed by sender.] On Mon, Jun 18, 2018 at 6:07 PM, learner dba mailto:cassandra...@yahoo.com.invalid>> wrote: Hi Sean, Are you using any rack aware topology? --> we are using gossip file Are you using any rack aware topology? --> we are using gossip file What are your partition keys? --> Partition key is uniq Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? --> No, we verified it. If it was partition key issue, we would see similar number of partition keys across nodes. If we look closely number of keys across nodes vary a lot. Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R mailto:sean_r_dur...@homedepot.com>> wrote: Are you using any rack aware topology? What are your partition keys? Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? Sean Durity lord of the (C*) rings (Staff Systems Engineer – Cassandra) MTC 2250 #cassandra - for the latest news and updates From: learner dba mailto:cassandra...@yahoo.com>. INVALID> Sent: Monday, June 18, 2018 2:06 PM To: User cassandra.apache.org<https://urldefense.proofpoint.com/v2/url?u=http-3A__cassandra.apache.org=DwMFaQ=MtgQEAMQGqekjTjiAhkudQ=aC_gxC6z_4f9GLlbWiKzHm1vucZTtVYWDDvyLkh8IaQ=8q4p6nWedWQJ9gpXCnoa6KR4HRmSf3B1whdYKNFub6M=TmzIaVextVyZy81p9JuU7R6PFv84RfhgtEezCe063V0=> mailto:user@cassandra.apache.org>> Subject: [EXTERNAL] Cluster is unbalanced Hi, Data volume varies a lot in our two DC cluster: Load Tokens Owns 20.01 GiB 256 ? 65.32 GiB 256 ? 60.09 GiB 256 ? 46.95 GiB 256 ? 50.73 GiB 256 ? kaiprodv2 = /Leaving/Joining/Moving Load Tokens Owns 25.19 GiB 256 ? 30.26 GiB 256 ? 9.82 GiB 256 ? 20.54 GiB 256 ? 9.7 GiB256 ? I ran clearsnapshot, garbagecollect and cleanup, but it increased the size on heavier nodes instead of decreasing. Based on nodetool cfstats, I can see partition keys on each node varies a lot: Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 N
Re: RE: [EXTERNAL] Cluster is unbalanced
We do not chose the node where partition will go. I thought it is snitch's role to chose replica nodes. Even the partition size does not vary on our largest column family: Percentile SSTables Write Latency Read Latency Partition Size Cell Count (micros) (micros) (bytes) 50% 0.00 17.08 61.21 3311 1 75% 0.00 20.50 88.15 3973 1 95% 0.00 35.43 105.78 3973 1 98% 0.00 42.51 126.93 3973 1 99% 0.00 51.01 126.93 3973 1 Min 0.00 3.97 17.09 61 0 Max 0.00 73.46 126.93 11864 1 We are kinda stuck here to identify, what could be causing this un-balance. On Tuesday, June 19, 2018, 7:15:28 AM EDT, Joshua Galbraith wrote: >If it was partition key issue, we would see similar number of partition keys >across nodes. If we look closely number of keys across nodes vary a lot. I'm not sure about that, is it possible you're writing more new partitions to some nodes even though each node owns the same number of tokens? On Mon, Jun 18, 2018 at 6:07 PM, learner dba wrote: Hi Sean, Are you using any rack aware topology? --> we are using gossip file Are you using any rack aware topology? --> we are using gossip file What are your partition keys? --> Partition key is uniqIs it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? --> No, we verified it. If it was partition key issue, we would see similar number of partition keys across nodes. If we look closely number of keys across nodes vary a lot. Number of partitions (estimate): 3142552Number of partitions (estimate): 15625442Number of partitions (estimate): 15244021Number of partitions (estimate): 9592992Number of partitions (estimate): 15839280 On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R wrote: Are you using any rack aware topology? What are your partition keys? Is it possible that your partition keys do not divide up as cleanly as you would like across the cluster because the data is not evenly distributed (by partition key)? Sean Durity lord of the (C*) rings (Staff Systems Engineer – Cassandra) MTC 2250 #cassandra - for the latest news and updates From: learner dba Sent: Monday, June 18, 2018 2:06 PM To: User cassandra.apache.org Subject: [EXTERNAL] Cluster is unbalanced Hi, Data volume varies a lot in our two DC cluster: Load Tokens Owns 20.01 GiB 256 ? 65.32 GiB 256 ? 60.09 GiB 256 ? 46.95 GiB 256 ? 50.73 GiB 256 ? kaiprodv2 = /Leaving/Joining/Moving Load Tokens Owns 25.19 GiB 256 ? 30.26 GiB 256 ? 9.82 GiB 256 ? 20.54 GiB 256 ? 9.7 GiB 256 ? I ran clearsnapshot, garbagecollect and cleanup, but it increased the size on heavier nodes instead of decreasing. Based on nodetool cfstats, I can see partition keys on each node varies a lot: Number of partitions (estimate): 3142552 Number of partitions (estimate): 15625442 Number of partitions (estimate): 15244021 Number of partitions (estimate): 9592992 Number of partitions (estimate): 15839280 How can I diagnose this imbalance further? -- Joshua Galbraith | Senior Software Engineer | New Relic C: 907-209-1208 | jgalbra...@newrelic.com
Re: RE: [EXTERNAL] Cluster is unbalanced
>If it was partition key issue, we would see similar number of partition keys across nodes. If we look closely number of keys across nodes vary a lot. I'm not sure about that, is it possible you're writing more new partitions to some nodes even though each node owns the same number of tokens? On Mon, Jun 18, 2018 at 6:07 PM, learner dba wrote: > Hi Sean, > > Are you using any rack aware topology? --> we are using gossip file > Are you using any rack aware topology? --> we are using gossip file > What are your partition keys? --> Partition key is uniq > Is it possible that your partition keys do not divide up as cleanly as you > would like across the cluster because the data is not evenly distributed > (by partition key)? --> No, we verified it. > > If it was partition key issue, we would see similar number of partition > keys across nodes. If we look closely number of keys across nodes vary a > lot. > > > Number of partitions (estimate): 3142552 > Number of partitions (estimate): 15625442 > Number of partitions (estimate): 15244021 > Number of partitions (estimate): 9592992 > Number of partitions (estimate): 15839280 > > > > > > On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R < > sean_r_dur...@homedepot.com> wrote: > > > Are you using any rack aware topology? What are your partition keys? Is it > possible that your partition keys do not divide up as cleanly as you would > like across the cluster because the data is not evenly distributed (by > partition key)? > > > > > > Sean Durity > > lord of the (C*) rings (Staff Systems Engineer – Cassandra) > > MTC 2250 > > #cassandra - for the latest news and updates > > > > *From:* learner dba > *Sent:* Monday, June 18, 2018 2:06 PM > *To:* User cassandra.apache.org > *Subject:* [EXTERNAL] Cluster is unbalanced > > > > Hi, > > > > Data volume varies a lot in our two DC cluster: > > Load Tokens Owns > > 20.01 GiB 256 ? > > 65.32 GiB 256 ? > > 60.09 GiB 256 ? > > 46.95 GiB 256 ? > > 50.73 GiB 256 ? > > kaiprodv2 > > = > > /Leaving/Joining/Moving > > Load Tokens Owns > > 25.19 GiB 256 ? > > 30.26 GiB 256 ? > > 9.82 GiB 256 ? > > 20.54 GiB 256 ? > > 9.7 GiB256 ? > > > > I ran clearsnapshot, garbagecollect and cleanup, but it increased the size > on heavier nodes instead of decreasing. Based on nodetool cfstats, I can > see partition keys on each node varies a lot: > > > > Number of partitions (estimate): 3142552 > > Number of partitions (estimate): 15625442 > > Number of partitions (estimate): 15244021 > > Number of partitions (estimate): 9592992 > > Number of partitions (estimate): 15839280 > > > > How can I diagnose this imbalance further? > > > -- *Joshua Galbraith *| Senior Software Engineer | New Relic C: 907-209-1208 | jgalbra...@newrelic.com
Re: RE: [EXTERNAL] Cluster is unbalanced
Hi Sean,
Are you using any rack aware topology? --> we are using gossip file
Are you using any rack aware topology? --> we are using gossip file What are
your partition keys? --> Partition key is uniqIs it possible that your
partition keys do not divide up as cleanly as you would like across the cluster
because the data is not evenly distributed (by partition key)? --> No, we
verified it.
If it was partition key issue, we would see similar number of partition keys
across nodes. If we look closely number of keys across nodes vary a lot.
Number of partitions (estimate): 3142552Number of partitions (estimate):
15625442Number of partitions (estimate): 15244021Number of partitions
(estimate): 9592992Number of partitions (estimate): 15839280
On Monday, June 18, 2018, 5:39:08 PM EDT, Durity, Sean R
wrote:
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Are you using any rack aware topology? What are your partition keys? Is it
possible that your partition keys do not divide up as cleanly as you would like
across the cluster because the data is not evenly distributed (by partition
key)?
Sean Durity
lord of the (C*) rings (Staff Systems Engineer – Cassandra)
MTC 2250
#cassandra - for the latest news and updates
From: learner dba
Sent: Monday, June 18, 2018 2:06 PM
To: User cassandra.apache.org
Subject: [EXTERNAL] Cluster is unbalanced
Hi,
Data volume varies a lot in our two DC cluster:
Load Tokens Owns
20.01 GiB 256 ?
65.32 GiB 256 ?
60.09 GiB 256 ?
46.95 GiB 256 ?
50.73 GiB 256 ?
kaiprodv2
=
/Leaving/Joining/Moving
Load Tokens Owns
25.19 GiB 256 ?
30.26 GiB 256 ?
9.82 GiB 256 ?
20.54 GiB 256 ?
9.7 GiB 256 ?
I ran clearsnapshot, garbagecollect and cleanup, but it increased the size on
heavier nodes instead of decreasing. Based on nodetool cfstats, I can see
partition keys on each node varies a lot:
Number of partitions (estimate): 3142552
Number of partitions (estimate): 15625442
Number of partitions (estimate): 15244021
Number of partitions (estimate): 9592992
Number of partitions (estimate): 15839280
How can I diagnose this imbalance further?
