Chunk Size is shown as 1 KB in mongo db logs even it is set to 300 MB

I am running a mongo cluster. Chunk size set is 300 MB but for today morning it is showing me in logs taht chunk size is 1024 Byte. I checked in current op there also it is showing chunks of 1024 byte. I have check with monos and all config server chunk size is 300 MB there.

Please help me to resolve the issue as it is all of teh sudden bringing my shard set up down. here is log from currentOp

 {
                    "opid" : "shard0000:-1945000000",
                    "active" : true,
                    "secs_running" : 0,
                    "microsecs_running" : NumberLong(72072),
                    "op" : "query",
                    "ns" : "ibeat20150102.locationCount",
                    "query" : {
                            "splitVector" : "ibeat20150102.locationCount",
                            "keyPattern" : {
                                    "articleId" : 1,
                                    "host" : 1
                            },
                            "min" : {
                                    "articleId" : { "$minKey" : 1 },
                                    "host" : { "$minKey" : 1 }
                            },
                            "max" : {
                                    "articleId" : { "$maxKey" : 1 },
                                    "host" : { "$maxKey" : 1 }
                            },
                            "maxChunkSizeBytes" : 1024,
                            "maxSplitPoints" : 2,
                            "maxChunkObjects" : 250000
                    },
                    "client_s" : "192.168.22.106:55881",
                    "desc" : "conn237027",
                    "threadId" : "0x7c6cc55db700",
                    "connectionId" : 237027,
                    "locks" : {
                            "^ibeat20150102" : "R"
                    },
                    "waitingForLock" : true,
                    "numYields" : 14,
                    "lockStats" : {
                            "timeLockedMicros" : {
                                    "r" : NumberLong(32978),
                                    "w" : NumberLong(0)
                            },
                            "timeAcquiringMicros" : {
                                    "r" : NumberLong(48048),
                                    "w" : NumberLong(0)
                            }
                    }
            },

Entry from setting

{ "_id" : "chunksize", "value" : 250 }

Error in primary shard

2015-01-02T13:04:48.386+0530 [conn237049] warning: chunk is larger than 1024 bytes because of key { articleId: "", host: "zigwheels.com" } 2015-01-02T13:04:48.386+0530 [conn237049] warning: chunk is larger than 1024 bytes because of key { articleId: "0", host: "happytrips.com" }

Seeing this in my mongos log for same collection

2015-01-02T14:53:58.983+0530 [conn58] warning: splitChunk failed - cmd: { splitChunk: "ibeat20150102.locationCount", keyPattern: { articleId: 1, host: 1 }, min: { articleId: MinKey, host: MinKey }, max: { articleId: MaxKey, host: MaxKey }, from: "shard0000", splitKeys: [ { articleId: "", host: "zigwheels.com" } ], shardId: "ibeat20150102.locationCount-articleId_MinKeyhost_MinKey", configdb: "192.168.24.192:27017,192.168.24.54:27017,192.168.24.55:27017" } result: { who: { _id: "ibeat20150102.locationCount", state: 1, who: "ibeatdb61:27017:1420185037:1475849446:conn913:869542099", ts: ObjectId('54a660afdc99ecfb22d83c27'), process: "ibeatdb61:27017:1420185037:1475849446", when: new Date(1420189871037), why: "split-{ articleId: MinKey, host: MinKey }" }, ok: 0.0, errmsg: "the collection's metadata lock is taken" }

I have taken these steps: 1. Stop read an write on servers 2. Stop mongos server 3. Restarted config servers. 4. Restarted mongos server 5. Restarted read and write. Still the same issue is appearing